BULLETINS OF THE Zoological Society oF San Diego No. 12 PHYLLORHYNCHUS, The Leaf-Nosed Snake BY L. M. Klauber Qavatov of Reptiles, Zoological Society of San Diego SAN DIEGO, CALIFORNIA SEPTEMBER 12,1935 Digitized by the Internet Archive in 2017 with funding from IMLS LG-70-15-0138-15 https://archive.org/details/bulletinsofzoolo1219unse OFFICERS OF THE ZOOLOGICAL SOCIETY OF SAN DIEGO BOARD OF DIRECTORS Harry M. Wegeforth, M.D., President F. L. Annable, Vice-President E. T. Olmstead, Secretary Frank C. Spalding, Treasurer Gordon Gray Keith Spalding W . C. Crandall Robert J. Sullivan G. Allan Hancock Dr. C. H. Townsend Mayor oe San Diego President of Park Commissioners EXECUTIVE STAFF Mrs. Belle J. Benchley, Executive Secretary Louis Gill, Architect John Morley, tiorticulturist Paul Avery, Landscape Architect L. M. Klauber, Curator of Reptiles C. R. SCHROEDER, D.V.M., Pathologist A. T. Mercier, Consulting Engineer HOSPITAL STAFF Dr. R. j. Pickard, Chairman Dr. Howard A. Ball Dr. Francis M. Smith Dr. Hall G. Holder Joshua L. Bailey Dr. Eaton M. MacKay W. C. Crandall H. C. Bingham, Ph.D. EDUCATIONAL COMMITTEE H. C. Steinmetz, Chairman Mrs. Lena P. Crouse Emma-Lindsay Squier AQUARIUM COMMITTEE W. C. Crandall, Chairman G. Allan Hancock Fred Lewis Gerald MacMullen Dr. Ceiarles FI. Townsend THE PURPOSE OF THE SOCIETY 1. To advance science and the scientific study of nature. 2. To foster and stimulate interest in the conservation of wild life. 3. To maintain a permanent Zoological Exhibit in San Diego. 4. To stimulate public interest in the building and the maintenance of a Zoological Elospital. 5. To provide for the delivery of lec- tures, exhibition of pictures and the publication of literature dealing with natural history and science. 6. To operate a society for the mutual benefit of its members for non-lucra- tive purposes. BULLETINS OF THE ZOOLOGICAL SOCIETY OF SAN DIEGO No. 12 PHYLLORHYNCHUS, THE LEAF-NOSED SNAKE BY L. M. Klauber Curator of Reptiles, Zoological Society of San Diego SAN DIEGO, CALIFORNIA SEPTEMBER 12, 193 5 4 Bulletin 12 : Zoological Society oe San Diego aJ^SO-LMff Klauber: The Leaf-Nosed Snake 5 PHYLLORHYNCHUS, THE LEAF-NOSED SNAKE Introduction The Leaf-nosed Snakes of the genus Fhyllorhynchiis are small, stubby snakes inhabiting the arid regions of the south- western United States and northwestern Mexico. Until re- cently they were considered extremely rare; now it is known that they are rather plentiful in many areas, but being noc- turnal, have not often been collected. Two species have been described, P. decnrtafus and P. browni. Both are characterized by the presence on the snout of a greatly enlarged rostral scale resembling a superimposed leaf, from which the generic and common names are derived. The first specimen of the genus was described in 1868 by Cope^ as T^hiniothyra deciirtata. In 1890 Stejneger“ estab- lished the genus VhyllorhyncJom for this and a second, newly discovered species, P. browni, which he then described. As an indication of the rarity of these snakes in museums it may be noted that, from the date of their discovery in 1868 to 1922, there were added to collections only 6 speci- mens of de curt atm and 4 of browni. More recently the motor car has so changed the technique of reptile collecting," particularly of nocturnal snakes on the desert, that a large amount of new material has become available; over 165 specimens, mostly of decurtatus, are now at hand and pre- viously known ranges have been considerably extended. It therefore appears desirable to review our knowledge of the genus, to consider the validity of the forms hitherto de- scribed, and to indicate the dispersion of characters shown by this new material, thus determining whether further subdivisions are advisable. iProc. Acad. Nat. Sci. Phila., 1 868, p. 310. 2Proc. U. S. Nat. Mus., 1890, Vol. 13, pp. 151-lU. ^Klauber, Bull. Zool. Soc. San Diego, 1931, No. 8, pp. 41, 61. 6 Bulletin 12: Zoological Society of San Diego The Validity of Phyllorhynchus browni Stejneger, in describing browni, distinguished it from de- c art at us on the basis of a number of characters, including stouter build, longer tail, keeled posterior dorsal scales, fewer ventrals, higher number of caudals, lack of lateral spots, and fewer dorsal blotches. Gradually, as additional specimens of the genus have come into collections, most of these charac- teristics have failed to hold; the tail-length ratio is found to overlap (the difference originally pointed out was prob- ably one of sexual dimorphism) ; the caudals overlap; lateral spots are sometimes faintly evident in browni; and in decur- fatus specimens are not wanting with strongly keeled pos- terior dorsal scales, for this is a sexual and territorial char- acteristic. As to the ventrals, while it is true that California specimens of decurtatiis have a distinctly higher number than are present in seven of the eight available specimens of browni, yet the Lower California, Sonora, and Pima County (Arizona) specimens of de curt at us overlap browni; and the most westerly known specimen of browni approaches the decurtatiis average. There remains, then, only the item of the body blotches, but here the difference between the two forms is so pro- nounced that I do not consider browni a subspecies of decur- tatus, as recently suggested by Linsdale.^ One hundred and fifty-nine specimens of decurtatus from California, Lower California, Nevada, Arizona, and Sonora have an average of 3 5.6 body spots, with an extreme range of variation of 20 to 48. Of browni only eight specimens are available; the body blotches on these number thirteen in three, twelve in three, and eleven in the remaining two; average 12.1. It need hardly be said that we have here a highly significant difference, for the minimum spots on decurtatus number nearly twice the maximum of browni, and the averages of the two forms are in the ratio of about three to one. Furthermore there is no tendency toward fewer spots in decurtatus as the territory of browni is approached; in other words no intergradation 4 COPEIA, 1933, pp. 222-223. Klauber: The Leaf-Nosed Snake 7 is indicated by material now available. The patterns of the two forms are also quite different in character. Thus it is necessary to conclude that the species are distinct. Such confusion as has existed in the past concerning the status of the two forms of the genus resulted from lack of material and the peculiarities of the ranges. For a long time broivni was known only from the vicinity of Tucson, Ari- zona, while decurtatm was thought to be essentially a Cali- fornia form, not having been collected east of Yuma; thus there was a gap of 200 miles between their known ranges. There was one troublesome specimen (AMNH 20590) from near Tucson which had 42 body spots; for territorial reasons this was catalogued as broivni^ thus breaking down the blotch-count as a key character. But additional material has shown that the ranges of the two forms overlap, for both occur in south-central Arizona; when this Tucson specimen is reclassified as decjirtatus the situation is at once made clear. Of course a question may be raised as to the propriety of separating two forms morphologically so similar, upon a basis of pattern, especially as their ranges overlap. In the present instance the numerical hiatus in the blotch count is so great that there appears little chance that intermediates will be found. In fact specimens of decjirfafns from broivni territory tend to have a high number of blotches; decurtatns, has the fewest spots in the Cape Region of Lower California and in southern Sonora, and there broivni does not occur. There remains the possibility that broivni is an expression of sexual dimorphism. This is doubtful, even though it ap- pears that all the specimens of broivni thus far available are males; this suggestion will be discussed later in considering territorial variations of characters. The Races of Phyllorhynchus decurtatus A study of available decurtatus material indicates that this species may be divided into two well defined races based on territorial differences in several characters. One of these races inhabits the southern part of Lower California, western Sonora, and southeastern Arizona; the other is found in the 8 Bulletin 12: Zoological Society of San Diego desert areas of southeastern California, southern Nevada, and western Arizona. It also certainly occurs in northeastern Lower California, although not yet reported from that area, and it will probably be found in southwestern Utah. The southerly subspecies is distinguished from the other by a lower ventral scale count, larger body blotches, darker color, and often (but not invariably) fewer blotches. These dif- ferences are subsequently discussed in detail. However, there is some difficulty in determining to which of these two races Cope’s original description applies, since the type specimen does not represent either of the extremes; rather it is intermediate in character and presumably it came from intermediate territory. Although the type speci- men has been available for examination, the type locality is not known; it is given by Cope as the "upper part of Lower California” where it was collected by Wm. M. Gabb. We know from Gabb’s itinerary^ that he turned westward to the Pacific at Mision San Fernando, reaching the coast at Rosario; thereafter he traveled north to Tijuana either along the coast or closely adjacent thereto. Phyllorhyii clous has never been reported from this area and from the nature of the country it may be presumed that it does not occur there. On the other hand it has been collected at San Ignacio and might be expected almost anywhere along Gabb’s route as far north as Mision San Fernando. Therefore the type lo- cality may be presumed to lie between these points; it could hardly be south of San Ignacio as it would not then have been referred to as "upper Lower California.” The specimens now available from San Ignacio are not as extreme in char- acteristics as are those from the Cape region of Lower Cali- fornia; the type specimen is even less so, yet on the whole its characteristics show it to be more nearly allied to the south- ern than the northern race. Therefore the type subspecies is considered to be the Cape-Sonora race, while the northern form is given a new name. ® Resources of the Pacific Slope, by J. Ross Browne, San Francisco, 1869. Appendix; Exploration of Lower California by Wm. M. Gabb, pp. 82-122. Klauber: The Leaf-Nosed Snake 9 Descriptions of Species Because of the additional material available it is deemed advisable to present summaries of the characteristics of all forms of the genus, whether new or old. Phyllorhynchus decurtatus decurtatus (Cope) Mexican Leaf-nosed Snare. 1868 Vhymortbyra decurtata Cope, Proc. Acad. Nat. Sci. Phila., Nov. 1868, p. 310. Type locality, "Upper part of Lower California;” type specimen No. 5489 in collection of Acad. Nat. Sci. Phila. 1 883 Salvadora decurtata Carman, Mem. Mus. Comp. ZooL, Cambridge, Vol. VIII, No. 3, pp. 39, 145. 1890 Phyllorhynchus decurtatus Stejneger, Proc. U. S. National Museum, Vol. XIII, p. 154. 1893 Lytorhynchus decurtatus Boulenger, Cat. Snakes British Museum, Vol. I, p. 417. 1901 Phyllorhynchus decurtatus (part) Brown, Proc. Acad. Nat. Sci. Phila., vol. 53, p. 64. 193 3 Phyllorhynchus decurtatus decurtatus (part) Linsdale, Copeia, No. 4 of 1933, p. 222. Material. — Six specimens from Lower California, four from Sonora, and three from southeastern Arizona; total thirteen. Lepidosis. — Scale rows at midbody usually 19, rarely 21 or 18. The dorsal rows may be keeled or smooth; there are both territorial and sexual variations. Males are more strongly keeled than females; the latter may be quite smooth even when from areas where the males are strongly ridged. Keeling, when present, is more definite posteriorly; the neck is usually smooth even where conspicuous ridges are elsewhere present. The central dorsal row is almost invariably smooth; such keeling as may exist is most conspicuous on the three rows bordering this on either side. Ter- ritorial variations within this subspecies are as follows: Sonora males are strongly keeled, southeastern Arizona material somewhat less so; Lower California specimens are virtually smooth, whether male or female. The dorsal scales are slightly smaller than the lateral rows. Ventrals: Males max. 168, min. 151, mean 156.7 (10 specimens); females, max. 176, min. 166, mean 171.3 (3 specimens). The anal is en- tire. The caudals are in two series; males, max. 3 5, min. 30, mean 3 3.5; females max. 26, min. 24, mean 2 5.3. The rostral is enlarged and raised, imbricate and with grooved lateral edges. It is concave below; above it is curved backward over the snout. The internasals are small and are separated by the rostral. The prefrontals 10 Bulletin 12: Zoological Society oe San Diego are larger; although they are usually in contact, in one case out of the thirteen they are separated by the rostral, and in two others there is a small extra scale between them; laterally they are curved down over the sides to meet the loreals. The frontal is large and pentagonal. The supra- labials are small and do not shade the eyes. The parietals are the largest of the head scales. The nasals are divided, the anterior partly roofing the nostril; the posterior is the larger. One loreal is always present; usually there is one subloreal, occasonally two, arranged horizontally; rarely there is a supraloreal. The preoculars are normally two, rarely three; post- oculars usually three, sometimes two, rarely one; suboculars one to three total ocular ring seven to nine. The temporals are irregular being from 2 + 3 to 4 + 4. The sLipralabials are normally six, sometimes five or seven; the last two are enlarged; usually the fourth and fifth contact the orbital scales. The infralabials are eight or nine; the initial pair is large, meeting behind the subtriangular mental. The genials, of which there is one pair, are in contact. Form . — This is a relatively short and stubby snake. The longest avail- able specimen, a male, is 3 32 mm.; the shortest 140 mm. The tail-length ratio varies from 12.7 to 16.4 per cent in the males, and from 8.3 to 9.4 in the females. The everted hemipenis is triangular and somewhat bifurcate; the distal ends have reticulate fringes edged with points; proximally there is a transi- tion to many short spines. The eye is protruding, with vertical pupil; in life the iris is flecked with gray and brown. The tongue is pinkish. Pattern and Color . — The primary pattern is a series of brown blotches on a gray-brown background. The blotches are irregular in shape, more so in the Lower California specimens than elsewhere in the range. In Sonora and Arizona they are usually elliptical, with the long axis perpendicular to the dorsal line; in Lower California they are squares or rectangles, often considerably indented and with uneven borders. The scales in the blotch centers usually themselves have light centers; thus the blotches appear to be hatched with thin longitudinal lines. The blotches at midbody are from 2 ka to 6 scales (end to end) long and seven to eleven scale-rows wide. Longitudinally they are greater than the interspaces. The blotches are somewhat darker anteriorly and on the neck there is frequently a particu- larly dark blotch of double length. On the sides there are one or more auxiliary series of spots, irregular in form, which may be the same or double the frequency of the main series. In some specimens, notably those from Sonora, these secondaries coalesce on the neck to form short longi- tudinal side bands. Between the blotches the ground color is heavily punc- tated with gray or brown, except for the mid-dorsal rows which are clearer and lighter. The dorsal ground-color is light brown or tan in life. Klauber: The Leaf-Nosed Snake 11 but grayish-white when preserved. The undersurfaces are immaculate, white or cream. The head is marked with a cross band across the prefrontals which passes downward and backward through the eye to the commissure. This band is perfect in some specimens (particularly those from Arizona), less so in others. On the parietals there are usually several small brown spots. The body blotches vary in number from 20 to 42, the average for 13 specimens being 31.0. The Cape specimens have the fewest blotches (3 specimens have 20, 24, and 23) followed by those from Sonora. There is considerable irregularity in the blotch count as in some specimens a sec- ondary series, almost equaling the primary in size, practically doubles the count. The blotches on the tail vary from 4 to 8, average 6.1. Range . — Specimens have been collected in the following localities: Lower California: "Upper Part of Lower California” (Type Locality) San Ignacio Bet. Loreto and Comondu La Paz Sonora: La Posa near San Carlos Bay, Guaymas San Carlos Bay, Guaymas Alamo Muerto, 3 0 mi. W. of Caborca Arizona: Tucson, Pima County San Xavier Mission, Pima County Coolidge, Pinal County Phyllorhynchus decurtatus perkinsi Subsp. nov. Desert Leaf-nosed Snake. 1901 Phyllorhynchns decurtatus (part) Brown, Proc. Acad. Nat. Sci. Phila., Vol. 33, p. 64. 193 3 Phyllorhynchus decurtatus decurtatus (part) Linsdale, Copeia, No. 4 of 1933, p. 222. Type. — No. 2 3737 in the collection of L. M. K. Collected at Dry Lake,'^ San Diego County, California, by L. M. K., May 4, 1933. ® Named for my good friend C. B. Perkins, in charge of reptiles at the Zoological Society of San Diego, who has been the source of much useful material, including an un- precedented series of rattlesnakes from Colorado. 7 Dry Lake is on the Narrows to Kane Springs road, 3 mi. west of the Imperial County line. It is a flat, but not especially sandy desert. The following paratypes are available from the same point: LMK 22260-1, 22295, 22297-8, 22741, 22954-5, 23027, 23386-7, 23750-6, 23758-61, 23815, 23846-8, 23911-3, 23918-23, 23951, 23995-7; total 39. 12 Bullehn 12: Zoological Sociliy of San Difgo Diagnosis. — A subspecies of Phyllorhynchiis dcciirtahts characterized by a high ventral scale count and small, widely separated body blotches. Description of the Type.^ — Adult male. Length overall (prior to set- ting in preservative) 441 mm.; length of tad 67 mm.; ratio of tail to total length IS. 2 per cent. The scale rows are 21-19-17. The seven dorsal rows are keeled; the keeling virtually disappears on the neck, first failing on the mid-dorsal row. The ventrals number 176; the anal is entire; the caudals number 3 9 and are in two series. The rostral is enlarged and prominent, as is typical of the genus; it is concave below and curved backward over the snout above. There is a pair of internasals, which are separated by the rostral; a pair of prefrontals in contact, followed by a large frontal, bordered by a small supraocular on each side. Then follows a pair of parietals, the largest of the head shields. The nasals are divided into two parts, the posterior larger. There is a loreal and subloreal on each side. There are two preoculars, two post- oculars, and two suboculars, making the ocular rings 7. The temporals are 3+4, 2+4. The surpralabials are 6 — 6, the last two being the largest; the infralabials are 9 — 8, the first two meeting on the median line; of the others the fifth on the right and fourth on the left are largest. The mental is triangular and strongly concave on the sides. There is a single pair of genials in contact. There are five scales between the genials and first ventrals. The ground color of the body is straw- white (vinacenus in life) upon which there is superimposed a series of 37 rectangular brown spots about 1 + scales long (end to end) and five scale-rows wide. The inter-blotch spaces are four or five scales long (end to end). On the sides there are two series of small spots somewhat irregularly dispersed. There are five blotches on the tail; others toward the tip are obsolete. On the dorsum (between blotches) 13 scale rows are punctated with brown, the mid-dorsal rows somewhat less than those on the sides. The scales constituting the dorsal blotches have light centers. The ventrals and first three lateral rows are white. The head is somewhat punctate. From each eye there is a short diagonal brown mark passing downward and backward between the fifth and sixth supralabials. General Summary oi Perkinsi Material. — The following will summarize the variations of perkinsi based on 151 specimens, 12 from Arizona, one from Nevada, and the balance from California, of which 40 are from the type locality. A num- ber of other specimens have been seen alive.. Lepidosis. — The scale rows at midbody are normally 19, a single speci- Purposely made brief to avoid duplication with the general summary of perkinsi 'ubscquently given. Klauber: The Leaf-Nosed Snake 13 men having 18. The complete scale roAv ^formula is usually 21-IV-19- 111*17. Theie is consideiable vaiiabihty on the neck, the 21 section being generally short, or it may be absent; sometimes there are 23 rows at thi's point. The second condensation (from 19 to 17) seems always present; it may occur slightly posterior to midbody, or nearer to the tail. Rarely there is a leduction to 15 at this point. The dorsal scales are usually smooth anteriorly, but may be keeled posteriorly, especially in the adult males. The dorsal scales are slightly smaller than the lateral rows. Ventrals: Males, max. 183, min. 166, av. 173.9 (91 specimens); females, max. 194, min. 181, av. 188.0 ( 52 specimens). It will be seen that sexual dimorphism is extensive; were it not for a single male from Yuma with 183 ventrals there would be no overlapping, for the next highest has 180. The anal is entire. Caudals: Males, max. 41, min. 32, av. 37.2 (90 specimens) ; females, max. 32, min. 26, av. 29.1 (52 specimens). The caudals are divided. The rostral (the most conspicuous characteristic of the genus) is greatly enlarged, with overhanging and grooved lateral borders. Below it is strongly concave; above it is recurved so as to separate the internasals, and partly divide the prefrontals. The internasals are small; the prefrontals are moderate in size and curve downward over the sides toward the lorcals. In one specimen the prefrontals are split longitudinally. The frontal is large and pentagonal. The supralabials are small and not imbricate over the eyes. The paired parietals are the largest of the head scales; they may be bordered posteriorly by a few enlarged scales; in one specimen they are fused posteriorly. The nasals are divided, the posterior being larger and higher. A true loreal of moderate size is always present; in addition there is usually at least one subloreal, or more often two (arranged horizontal- ly). Sometimes there is a supraloreal, split from the top of the true loreal. Thus the loreals are one in 10 per cent of the cases, two in 70 per cent, three in 17 per cent, and four in 3 per cent. The preoculars are normally two; there are three in 8 per cent of the specimens and one in 1 per cent. The postoculars are usually two; occasionally three (5 per cent), or one (4 per cent). In three cases the postoculars are fused to the supraoculars, in one specimen to the parietals. Suboculars vary from one to four, the distribution in per cent being as follows: one (1), two (48), three (50), four (1). Thus the orbital ring, while normally 7, is often 8, occasionally 9, rarely 6, and in one case 5. The temporals are highly variable; while often 2 + 3 or 3+3, the first row may number as many as 5 and the second as high as 6. The supralabials are normally six (83 per cent); occasionally seven (16 per cent), rarely five (1 per cent). Ordinarily the last two are the largest; when there are six the fourth and fifth contact the orbital scales. The Infralabials vary from seven to ten, the distribution being as follows in per cent; seven (4), eight (43), nine (51), ten (2). The initial pair is large; they meet behind the mental which is deeply indented on the sides. Of the others any from the second to the fifth may be the largest. 14 Bulletin 12: Zoological Society of San Diego There is a single pair of genials in contact; the next posterior pair of scales are often considerably enlarged and are usually separated by a scale. There are from 3 to 6 scales between genials and ventrals; usually 5. Form. — Phyllorhynchiis decnrtatiis perkinsi is a small snake, rather stubby and cylindrical in form, with a blunt tail. The head is slightly dis- tinct from the neck; it represents about 3.3 per cent of the length overall. The longest specimen recorded (a male) is 485 mm. (19.1 in.) overall; the shortest 165 mm. (6.5 in.). Specimens exceeding 450 mm. are not unusual in San Diego County. Males reach a slightly greater length than females. There is a considerable sexual dimorphism in tail length; in the males the tail is from 11.2 to 16.3 (average in 88 specimens 14.3) per cent of the length of the body overall; in the females the corresponding figures are 8.0 to 10.8 (average in 5 0 specimens 9.6 per cent.)"'* The everted hemipenis is triangular, being wide distally. Although there is a deep vertical groove on each side the organ is only slightly bifurcate with sulcus divided distally. At the top there are transverse striations. These merge on the sides into fringes, reticulate and edged with points; proximally there is a gradual transition to many short, heavy spines, closely and evenly distributed. This transition seem to be more gradual than in cl. decnrtatiis or broivni and the proximal spines pro- portionately heavier in perkinsi. In life the eye is protruding, the iris flecked with gray and with brown near the vertical pupil. The pupil is held vertical regardless of the angle of the head. The expansion of the pupil in darkness is both vertical and horizontal, but the latter predominates. The two eyes seem to have considerable independence of action in rotary motion. The tongue is white at the tip, otherwise pinkish. Pattern and Color. — Perkinsi is quite variable in both pattern and color. The former consists essentially of a series of squarish or rectangular dorsal spots of brown to the number of from 24 to 48 (males average 34.7, females 3 8.0, both sexes 3 5.9). The spots are often in the form of short cross-rectangles, with the edges indented on the central dorsal line. Usually they extend from 1 1(4 or 2 scales end-to-end, laterally covering ® The variation within each sex is partly the result of the fact that sexual dimorphism in this character increases with age, a condition which I have found to exist in other genera as well. The relation between tail length and body length is linear but with a constant term; in P. decurtatus it approximates, for the males, T=0. 174L-1 1 .2 ; and for the females T=0.10}L-2.4, both T, the tail length, and L, the length overall, being expressed in millimeters. Hence, taking snakes 200 and 400 mm. in length, we find that in the males the tail ratio increases (in passing from the juvenile to adult stage) from 1 1.8 to 14.6 per cent, while in the females the increase is from 9.0 to 9.7 per cent, thus showing the effect of the male organs contained in the tail. There is virtually no overlap m the T/L ratio, if size be taken into consideration, although adult females closely ap- proach some juvenile males in this characteristic. These determinations were largely made on fresh specimens prior to the shrinkage resulting from setting in preservative, which shrinkage affects the tail and body differently. Klauber: The Leaf-Nosed Snake 15 from 5 to 7, rarely 9, central dorsal rows. The separation is generally greater than the spot width. The dark scales comprising the spots usually have light centers. In addition to the main dorsal series there is at least one and often two or three secondary series of smaller spots on the sides. These are rather irregular in disposition; they may be of the same or double the frequency of the main series. In one specimen the main dorsal series is absent, but the auxiliary series is clearly evident. On the tail there are from 2 to 9 spots; these often cannot be counted with accuracy as they fade out toward the tail-tip. In addition to these spots the sides above the second or third row, and, less often, the central dorsal area as well, are stippled with brown, some- times so thickly and darkly as to render the dorsal series of blotches in- conspicuous. The ground color, dorsally, is pinkish or vinaceous in life; in preservative this fades to a dirty white. This is a true color, not the result of translucence of the skin, as can be clearly seen in life along its lower borders, where it is often patchy, or on the tail where less com- plicated by darker punctations. The head is irregularly spotted. Often the only mark is a broken brown band across the anterior part of the frontal, thence passing down- ward and backward across the eyes to the supralabials. This is generally less distinct and regular than in broivni or deciirtatm decurtatiis; it is more prominent in the Mohave than in the Colorado Desert specimens; often it is entirely absent. Live specimens of perkinsi from the type locality in San Diego County have the following coloration: Head Pale Grayish Vinaceous’ with a few scattered Sorghum Brown Spots; dorsal blotches Sorghum Brown with somewhat lighter centers; dorsal area between blotches Vinaceous Pink, lateral areas Vinaceous Buff; lower lateral areas and ventral surface White. Range. — Perkinsi is widespread throughout the deserts of the south- west, as is indicated by the following locality records: CALIFORNIA: San Diego County: Dry Lake (Type Locality) ” Sentenac Canyon Yaqui Well The Narrows Borego Valley San Felipe La Puerta N. end of Borego Mt. Capitalized colors refer to Ridgway, Color Standards and Nomenclature, 1912. Actually, specimens have been collected in every one of the 20 miles on the high- way from Sentenac Canyon via Yaqui Well, The Narrows, and Dry Lake to the County Line, but only these named points are listed, the specimens having been allocated to the nearest. 16 Bulletin 12: Zoological, Society ol San Diego Imperial County: Mountain Springs Myers’ Creek Bridge (on U.S. 80) Plaster City Kane Spring 9, 12 mi. NW. of Kane Spring 28 mi. SE. of Oasis Arroyo Salada Bridge (on U.S. 99) Bailey’s Well Near Brawley 4 mi. W. of Midway Well Bet. Gray’s and Midway Well 10 mi. W. of Yuma Pilot Knob Araz Andrade Riverside County: Tahquitz Creek Bet. Cabazon and Palm Springs Palm Springs 10 mi. SE. of Palm Springs Indian Wells Cathedral City 3 mi. S. of Coachella Travertine Rock Desert Center 14 mi. W. of Blythe San Bernardino County: 3 Yz mi. E. of Summit Near Victorville Bryman Helendale Barstow Nebo Gale Newberry Springs Troy Argos Ash Hill 2 mi. W. of Topock Bridge 3, 6 mi. S. of Needles Goffs Twentynine Palms Kern County: Inyokern Inyo County: Mesquite Spring Panamint Mts. vie. of Goler Canyon NEVADA: Clark County: 5 mi. SW. of Glendale 10, 15 mi. SE. of Las Vegas ARIZONA: Yuma County: Yuma Ligurta Adonde 8 mi. W. of Wellton Tacna Colfred Mojave County: Kingman McConnico 7, 10 mi. SW. of Oatman Maricopa County: NW. of Wickenburg at Yavapai Co. line (Dc- ciirtatus-perkinsi inter- grade) Klauber; Teie Leaf-Nosed Snake 17 Phyilorhynchus browni Stejneger Pima Leaf-nosed Snake. 1890 Phyllorhyiu'bns brown/ Stejneger, Proc. U. S. National Museum, Vol. XIII, p. 152. Type locality, Tucson, Arizona; type specimen, USNM No. 15719. 1893 Lytorhyncbus brownn Boulenger, Cat. Snakes British Museum, Vol. I, p. 417. 193 3 Pbyllorbyncb//s decurtaf/is browni Linsdale, Copeia, No. 4 of 1933, p.'222. Lepiclosis. — Scale rows 21-19-17, the first row dropped being the fourth, the second, the third. The 21 and 17 sections are short, the first on the neck, the other anterior to the vent. The dorsal scales are smooth anteriorly, and are usually keeled at midbody and tail (only males ex- amined). The ventral scales vary from 156 to 172; average for 8 specimens 160.1. These are all males; from analogy with perkinsi it may be antici- pated that the female counts will be considerably higher. The anal plate is entire. The caudals, which are di\dded, vary from 3 0 to 40; average 32.6. The rostral is large and conspicuous; it is raised and with free borders. Below it is concave; above recurved, separating the internasals, and, an- teriorly, the prefrontals. The internasals are small; the prefrontals some- what larger and curved over the sides. In one specimen there is an extra scale betw'een the prefrontals. The supraoculars do not jut over the eyes; they are separated by a large pentagonal frontal. The parietals are the largest of the head scales. The nasals are divided. The loreals number from one to four, there being usually at least one subloreal present. There are two or three preoculars, two to four postoculars, and two or three sub- oculars; thus the ocular ring varies from seven to ten. The temporals may be 2 + 3, 2+4, 3 + 3, or 3+4. The supralabials are normally six but occasionally seven; the infralabials eight or nine. Of the supralabials the last two are the largest. The first infralabials meet on the median line; the mental is subtriangular . and indented laterally. There is a single pair of genials. Form. — Browni is a small, stubby snake with a blunt tail, and with head only slightly distinct from the neck. The longest specimen measured was 345 mm. (13.6 in.), the shortest 166 mm. (6.5 in.g The tail length ratio (all specimens males) varies from 10.8 to 13.6 per cent (average 13.0). The tail may not be quite complete in the specimen having the lowest ratio. The hemipenis is somewhat bifurcate; on the distal ends the fringes are reticulate and edged with points, while proximally there is a gradual transition to many short heavy spines, evenly spaced. The spines may be, proportionately, slightly smaller and thinner than in per kinsi, but the limited material makes this uncertain. 18 Bulletin 12: Zoological Society oe San Diego The pupil of the eye is vertically elliptical. Pattern and Color . — The pattern of hroivni consists of a series ( 1 1 to 13, average 12.1) of red-brown, dorsal blotches. These are even-edged and in strong contrast with the ground color, much more so than in decnrtatns. They are rather variable in shape; they may be circular or elliptical, and, if the latter, usually have the long axis longitudinal, but occasionally transverse. Some are dumb-bell shaped. Often the largest blotches have light centers. There are from two to four additional blotches on the tail. The ground color is white or cream in preservative. The ventral surface is immaculate. Usually the dorsal blotches extend to the third or fourth lateral scale- rows. The area between the blotches is generally punctateti, particularly on the sides. Rarely a secondary series of small spots is faintly in evi- dence on the lowest side rows. On the head the only mark is a brown crescent crossing the frontal, and extending backward across each eye to the angle of the mouth. A live browni from Sabino Canyon, was colored as follows: Centers of dorsal blotches Fawn, outer edge Light Seal Brown; mid-dorsal inter- blotch areas Vinaceous Buff, laterally speckled with Fawn; lower lateral areas and ventral surface White. (Capitalized colors refer to Ridgway.) Range . — Thus far browni has been taken only at Tucson, (the type locality), San Xavier Mission, and Sabino Canyon (Santa Catalina Mountains), Pima County; and near Desert Wells (11 mi. E. of Mesa), Maricopa County, Arizona. A snake reported from Granite Gap, Flidalgo County, New Mexico,^' was probably of this species, but was not definitely identified. Discussion of Species Differences The difference between browni and decnrtatns is exclusive- ly one of pattern; in all other particulars the relationship is obvious and close. As the two forms occupy the same ter- ritory and ecological niches they cannot be separate sub- species — they are either full species or identical. The pattern differences, consisting of a wide separation in the number of body blotches (range 11-13 in browni, 20-48 in decnrtatns, corresponding averages 12.1 and 3 5.6), the nature of the blotches, and the virtual lack of secondaries in browni, are conspicuous and definite. Yet against this there are certain considerations which must not be overlooked: 1. Decnrtatns from browni territory exhibits the Medden, Copeia, 1927, No. 64, p. 82. Klauber: The Leaf-Nosed Snake 19 same scale characteristics as hrowni, i.e., the ventrals are fewer than in decuvfcitus elsewhere, the caudals are fewer, an inter-prefrontal scale is occasionally present. The diagonal stripe on the head is particularly con- spicuous on browni and more so in dc curt at us from southeastern Arizona than in the latter species from other areas. The amount of keeling is about the same in the two forms from the Tucson area. 2. The single specimen of browni from beyond the immediate vicinity of Tucson presents the same increas- ing tendency in scale counts as is shown territorially by de curt at us; that is, an increase from Tucson toward western Arizona. This specimen, taken by Earl Sanders not far from Mesa, Arizona, has 172 ventrals and 40 caudals, compared with a maximum of 160 and 3 3 in the Tucson group (all males). The blotches are smaller and darker in color than those from around Tucson, but in number and shape of blotches this specimen is just as distinctive as the others. 3. All of the eight available specimens of browni are males; thus the distinctive pattern may be a sexual char- acter. However, this preponderance is not so remark- able in view of the fact that ten of the thirteen speci- mens of decurtatus dccurtatus are males, and of HO specimens of perkinsi two-thirds are males. The theory that the browni form might be a manifestation of sexual dimorphism was canvassed by Schmidt in 1922. He concluded that this was impossible, since USNM 62 5 61 was reported by Stejneger to be a female. I have re-examined this specimen and it appears to me to be a male, as is also indicated by the low ventral scale count. Thus all eight known specimens of browni are appar- ently males. The problem is somewhat analagous to that of Lainpro- peltis getulus boylii and L. californiae. Just as L. californiae is found in only a small part of L. g. boylii territory, so also browni is much more restricted than decurtatus. No browni- 20 Bulletin 12: Zoological Soc.ii-ty oi San Diixa) dccurfatus mixtures have yet come to light, while boylii- califoruiac intergrades are not uncommon. Upon the evidence thus far available we conclude that hrowiii and dccurfatus are distinct species. The Validity of Perkinsi In segregating the two subspecies of dccurfatus it becomes important to determine the consistency of the characters upon which the segregation is predicated. As a basis upon which to build we shall take perkiusi as found in California. This group is selected because it seems homogeneous and is the only territorial form available in suf- ficient numbers to permit the necessary computations. The most important diagnostic characters are ventrals, body blotches, and pattern. In these the California specimens appear quite consistent; only the eastern San Bernardino County specimens show a slight tendency toward the reduc- tion in ventrals which is characteristic of the northwestern Arizona specimens. Summarizing the California specimens, of which there are 82 males and 5 3 females, we have the fol- lowing statistics: California Perkinsi Vent rah Body Spots Males Females Males Fein ales Extreme range 167— 180 181—194 24—46 3 0—48 Interquartile range 172.1 — 176.5 186.1 — 190.2 31.9—37.8 35.0 — 10.9 Mean 174.3 188.2 34.8 37.9 Probable error of the mean ±0.25 ±0.29 ±0.32 ±0.32 Coefticient of variation (per cent) 1.9 1.6 12.5 11.4 Thus we find the variation of the ventrals to be quite re- stricted. There is no overlap between the sexes. The adher- ence to the normal curve is not particularly close but this is probably a result of the relatively few specimens available and the large territory covered; rattlesnake studies indicate that the ventrals in a homogeneous and terriorially restricted group closely approach a normal distribution. Rlauber: The Leaf-Nosed Snake 21 The blotches have a wider dispersion; the curve is skewed, not normal, with a tail toward the higher numbers. This peculiar distribution results from the fact that between the main dorsal blotches there is a secondary series which some- times intersperses spots of equal size and quality with the primary series, especially on the neck, and when this is the case the normal series of about 3 5 blotches is increased into the forties. As the curve is skewed the interquartile range cannot be considered accurate. The western Arizona pcrkhisi differ somewhat, but not conspicuously, from the California specimens. Here we find that ten males have an average ventral count of 171.1 and the single female 189. The corresponding body spot averages are 34.3 and 41.0. Hence we see that these Arizona speci- mens fall about 3 or 4 below the California average in ven- trals; there is no essential deviation in the body spots. The western Arizona specimens thus are more closely allied to the California form (perkinsi) than to the southeastern Ari- zona d ecu r fat us deciirfafiis. The differences between de curt at us and perkinsi are more definite and extensive. We have the following: Dccnrtafiis Perkinsi (Lower Calif., Sonora, (California, SE. Arizona) W. Arizona) Ventrals Males, range in-168 166-183 Males, average 156.7 173.9 Females, range 166-176 181-194 Females, average . . 171.3 188.0 Caudals Males, range 30-35 3 2-41 Males, average 33.5 37.2 Females, range 24-26 26-32 Females, average 25.3 29.1 Thus the avera ge difference in the ventrals is about 1 0 per cent, which is highly significant where the coefficient of variation in one of the forms is about 2 per cent. In pattern the conspicuous difference between the two forms is in the comparatively larger blotches in dc curt at us 22 Bulletin 12: Zoological Society of San Diego deciirtafiis with proportionately reduced interspaces; also the typical form is usually darker in life. Certainly subspecific differentiation between these two forms is warranted. A specimen from a few miles north of Wickenburg, Mari- copa County, Arizona, near the Yavapai County line, taken by Earl Sanders, has 164 ventrals and the dorsal blotches are about equal to the interspaces. Thus it falls between typical dccurtatiis and per kin si and may be taken as indicating an area of intergradation between the two forms, which should extend from this point southward into Sonora. Another area of intergradation is to be expected on the east coast of north- central Lower California. In this species, as in certain other genera, as for instance Lichanura, Tanfilla, and Trimorpbodon, we observe that Arizona (particularly southeastern Arizona) specimens are more closely allied with southern Lower California individ- uals than with those from California. Lurthermore we find, as is often the case, that the Mohave Desert specimens are closer to those of Arizona and Lower California than the Colorado Desert specimens, for in perkinsi the Mohave snakes are likely to have larger blotches than have those from San Diego and Imperial Counties; also they are more heavily punctated. Within decurtatus dccurtatiis the principal territorial va- riations are in scales and pattern. Sonora males are strongly keeled while those from Lower California are smooth or nearly so. Also the former tend toward close-set, even, ellipti- cal blotches, while the latter generally have square marks with highly irregular boundaries. However, for the present it appears inadvisable to make a further separation into three subspecies, for the Sonora-Lower California differences are not substantiated by differences in ventral scale counts, as is the case between d. decurtatus and d. perkinsi. Addi- tional material in the future may indicate the desirability of a further subspecific division between the Lower California specimens on the one hand and those from Sonora and south- eastern Arizona on the other. Klauber: The Leaf-Nosed Snake 23 The Habits of the Leaf-nosed Snake The following notes, while largely based on specimens of perkinsi, are probably equally applicable to the other forms and in a few instances are based on them. Most of the early specimens of dccurfafiis or perkinsi were collected by overturning stones or fallen cacti. Thus up to 1922, only 6 specimens had come to light. Now, with the new technique of night collecting of desert snakes by auto, It is not unusual to secure three or more specimens in an evening and on one occasion no less than 12 specimens (6 alive and 6 run over) were collected by two automobiles working the same territory between 7:30 and midnight; one week later (June 1) a single auto collected 9. These snakes are not as subterranean as are, for instance, Lepfofyphlops and Auiiiella; they are merely nocturnal and it is only necessary to look for them against a background where they can be readily detected. Thus, if one drives slow- ly along an oiled or paved desert road at night, all of the desert snakes, being light in color, stand out brilliantly in the glare of the headlights as they cross the highway. This collecting method is found more fruitful than the laborious plan of working cross-country with a hand flash-lamp, ow- ing to the far greater territory covered by motor and the difficulty of discovering the spotted desert forms in their normal habitat where stones and twigs abound. I have not yet had the opportunity to try the auto scheme in hroivni territory. Just as the coastal diurnal snakes are most easily taken in spring, so it appears that the desert nocturnal snakes are most active in the same season. There are also indications (not yet definitely verified) that the dark of the moon is preferable and that the early evening (say 7:30 to 9 p. m.) is a better time to collect than later. However, they have been taken as late as 2:30 a. m. I have never found Phyl- lorhynchus abroad before dark as is occasionally the case with such desert night snakes as Arizona elegans occiden falls or Sonora occipitalis; I have even found the latter active be- fore sunset, although this is quite exceptional. 24 Bulletin 12; Zoological Society of San Diego One evening in early June we collected 9 specimens of perkinsi between 7:30 and 11:10; the temperature was from 83° to 86° F. Three days later the temperature had risen to 116° in the daytime and about 93° to 95° at night and leaf- nosed snakes were distinctly scarcer, although not entirely absent. While Phyllorbytichits is a desert denizen it cannot endure a temperature of 115° F. even when kept in the shade. These snakes must therefore seek refuge in deep rodent holes in the daytime, since they could hardly burrow deeply enough to protect themselves from the terrific surface heat, especially as they are not restricted to areas of loose sand. It woidd seem that pcrki/isi is more plentiful in some sec- tions of the desert than in others of similar characteristics, at least we have had more luck finding them in certain places. At such points they are the most common snake; at others they are probably exceeded by Sonora occipitalis, Arizona elegans occidenfalis, and Crofaliis cerastes. They are absent or rare in the irrigated sections of the desert, such as the fields of the Coachella and Imperial Valleys, thus indicating a preference for the original arid conditions. While appar- ently preferring habitats where there is some sand they are found in rocky situations as well, as, for instance, at various points on the desert slope of the mountains in San Diego County. Thus Phyllorhynchus deciirtatiis has a wider range than Crotalus cerastes, the most highly specialized of the desert snakes. I have not collected perkinsi in the belt of sand hills (about 3 mi. wide) west of Yuma, where both S. occipitalis and C. cerastes are found; probably it does not prefer an all-sand habitat. In captivity the leaf-nosed snake usually burrows in sand or hides under debris. While the exaggerated nose-shield is undoubtedly of advantage in burrowing it probably is not entirely the result of a burrowing habit. Salvadora has a sim- ilar rostral and does not seem to be a borrower. Certainlv the reinforced, but blunt, rostral of Pbyllorhynchus is not to be compared in effectiveness of adaptation with the shovel- shaped and overhanging snouts of Sonora occipitalis or Cbi- lotneniscus cinctns; the latter go into sand seemingly without Ki.auber: The Leaf-Nosed Snake 25 effort, but Phyllorhyuchus must press the sand out of the way with side-movements of the head. It usually takes from one to two minutes to bury itself, as it pauses several times en route. S. occipitalis and C. ci/ictiis go in considerably faster. In captivity P. iL pcrkinsi spends less time buried in sand than S. occipitalis or C. ductus; nevertheless it will often remain under sand in the daytime and seems to be en- tirely comfortable when buried to a depth of several inches. It does not have the habit, so often seen in S. occipitalis and especially C. ductus, of lying in the sand with snout and eyes exposed for observation. A specimen of P. d. decurtatus from San Ignacio seemed to spend more time above ground than P. d. pcrkinsi from the Colorado desert. Dr. E. H. Taylor has collected specimens of decurtatus decurtatus at night on the beach of San Carlos Bay near Guaymas. Another was found crawling on a wet flat after a rain. Phyllorbyncbus defends itself by assuming a striking coil with retracted neck and head. It lunges forward with a slight hiss and sometimes opens the mouth when striking. Prob- ably its worst enemy, since they are active at the same time and inhabit the same localities, is Arizona elegans occiden- talis, which is known to feed upon it, as well as on other snakes, lizards, and mammals. Little is known concerning the food habits of the leaf- nosed snakes. Presumably they eat insects and lizards; but in the spring they seem to feed largely on lizard eggs, espe- cially those of Coleonyx variegatus. Thus of 11 specimens in one lot, collected in late May, 5 contained lizard eggs. One contained 11 such eggs in all stages of digestion from the full egg to the folded empty sheath about to be ex- creted. A young adult specimen of perkinsi, when placed in a bag with several Coleonyx variegatus ate the tails off of two. The tails had not previously been dropped, thus indi- cating that the snake must have seized them with the usual result. The lizards were too large to have been eaten entirely, although a large leaf-nosed snake could easily eat a small gecko and has been observed to do so in captivity. Out of 21 26 Buli.etin 12: Zoological Society ol San Diego geckos caught one night 5 had recently lost their tails, no doubt partly the result of leaf-nosed attacks. In captivity the leaf-nosed snake drinks water readily, although it can rarely have access to water in the wild. Phyllorhynchus usually lays from 2 to 4 eggs (7 individ- uals noted with 4 eggs, 2 with 3, 1 with 2) . The eggs of two specimens were measured; the hrst, 428 mm. over all con- tained 3 eggs about 10x3 5 mm.; the second, 327 mm. long contained 2 eggs, 8x37 mm. The eggs seem very large pro- portionate to the size of the snake. Specimens of the leaf-nosed snake have been found with the vermilion colored mites which afflict many of our south- western reptiles. Acknowledgments I wish to thank the following individuals and institutions for the loan or gift of useful material: Drs. L. Stejneger and Doris M. Cochran, IJ. S. National Museum; Mr. J. R. Slevin, California Academy of Sciences; Dr. G. K. Noble, American Museum of Natural History; Drs. Jos. Grinnel and Jean Linsdale of the Museum of Verte- brate Zoology, University of California; Drs. R. B. Cowles and Walter Mosauer, and Mr. Chas. M. Bogert, University of California at Los Angeles; Drs. Witmer Stone and H. W. Fowler, Academy of Natural Sciences of Philadelphia; Dr. A. H. Wright, Cornell University; Dr. E. H. Taylor, Uni- versity of Kansas; Mr. H. R. Hill, Los Angeles Museum; Mrs. Helen T. Gaige and Mr. H. K. Gloyd, University of Michigan; the late Mr. A. H. Schlanze, Andrade, California; Messrs. Earl Sanders and R. E. Love, Mesa, Arizona; Mrs. Belle Benchley and Mr. C. B. Perkins, San Diego Zoological Society; Mr. David Regnery, San Diego; Mr. E. E. Benson, Dry Lake. Mr. L. H. Cook has been of much assistance to me in the making of scale counts. Klauber: The Leae-Nosed Snake 27 Summary and Key Phyllorhyjichus de cur tat ns and P. browiii are distinct species having overlapping ranges; their principal difference is in body pattern. P. deciirtatiis per kin si is described as a new subspecies from California, western Arizona and south- ern Nevada; it differs from the typical form as found in southern Lower California, Sonora, and southeastern Arizona in having a greater number of ventral and caudal scales, and smaller, more widely separated blotches. A. Dorsal body blotches (not including tail) less than 16 PJoyllorhynchus hrowui (Pima and Maricopa Counties, Arizona; prob- ably also southwestern New Mexico.) AA. Dorsal body blotches more than 18 PhyUorhyn clous decurtatus B. Ventrals usually number less than 167 in males and 179 in females; body blotches wider (along dorsal line) than interspaces P. d. decurtatus (Central and southern Lower California; western Sonora; south-central Arizona.) BB. Ventrals usually number more than 167 in males and 179 in females; body blotches narrower (along dorsal line) than interspaces P. d. per kin si (Desert and arid sections of California east of the Sierras and San Jacintos from the Death Valley region southward; northeastern Lower Cali- fornia; southern Nevada; western Arizona.) 28 Bulletin 12: Zoological Society of San Diego Annotated Bibliography Atsatt, Sarah R. 1921 A snake New to California. Copeia, No. 96, pp. 3 8-39. Announcement of the first California specimen. 1923 Behavior of the Leaf-nosed Snake, Phyllorhynchus deciirtatits. Univ. of Calif. Pubs, in Zook, Vol. 21, No. 9, pp. 303-3 12. Extensive observations on the first California specimen in captivity. Brown, A. E. 1901 A Review of the Genera and Species of American Snakes North of Mexico. Proc. Acad. Nat. Sci. Phila., Vol. 53, pp. 10-110. Description of the first specimen of decttrfafiis reported from the United States (pp. 64-65). Cope, E. D. 1868 Sixth Contribution to the Elerpetology of Tropical America. Proc. Acad. Nat. Sci. Phila., 1868, pp. 305-3 12. Original description of the first Phyllorbym'hiis discovered. P. deciirtatiis described as Phirnothyra decurtata (p. 310). 1900 The Crocodilians, Lizards, and Snakes of North America. Ann. Rept. U. S. Nat. Mus., 1898, pp. 1 5 3-1294. Descriptive summary (pp. 821-824). Klauber, L. M. 1924 Notes on the Distribution of Snakes in San Diego County, Cali- fornia. Bull. Zool. Soc. of San Diego, No. 1, pp. 1-23. The second California specimen (p. 11). 1931 A Statistical Survey of the Snakes of the Southern border of California. Bull. Zool. Soc. of San Diego, No. 8, pp. 1-93. Range and habitat. 1932 Amphibians and Reptiles Observed Enroute to Hoover Dam. Copeia, No. 3 of 1932, pp. 118-128. Demrtatm in Nevada (p. 125). Linsdale, J. M. 1933 The Leaf-nosed Snake in Sonora, Mexico. Copeia, No. 4 of 1933, pp. 222-223. Occurrence of decurtatns in Sonora and suggestion that browni is a subspecies of decurtatns. Medden, Rhena V. 1927 Notes on Phyllorhynchus. Copeia, No. 164, pp. 82-83. A specimen of decurtatns from California and probable occur- rence of browni in New Mexico. Klauber: The Leaf-Nosed Snake 29 Mosauer, W. 1932 Adaptive Convergence in the Sand Reptiles of the Sahara and of California: A Study in Structure and Behavior. Copeia, No. 2 of 1932, pp. 72-78. Character of nostril. Ortenburger, a. I. and Ortenburger, R. D. 1926 Field observations on some Amphibians and Reptiles of Pima County, Arizona. Proc. Okla. Acad, of Sci., Vol. 6, pp. 101-121. Capture of a specimen of hrowni (p. 116). Schmidt, K. P. 1922 The Amphibians and Reptiles of Lower California and the Neighboring Islands. Bull. Am. Mus. Nat. Hist., Vol. 46, pp. 607-707. Discussion of differences between hrowni and decurfafus (pp. 683-687). Slevin, J. R. 1931 Range Extensions of Certain Western Species of Reptiles and Amphibians. Copeia, No. 3 of 1931, pp. 140-141. Decurtatns in Inyo County, a new northern record. Stejneger, L. 1890 On a New Genus and Species of Colubrine Snakes from North America. Proc. U. S. Nat. Mus., Vol. 13, pp. 151-15 5. Original descriptions of the genus Phyllorhyncbits and the species P. hrowni. Van Denburgei, J. 1922 The Reptiles of Western North America. Occ. Papers Cal. Acad, of Sci., No. 10, pp. 1-1028 (2 vols.). Complete descriptions (pp. 692-697). VoRHiES, Chas. T. 1926 Notes on Some Uncommon Snakes of Southern Arizona. Copeia, No. 157, pp. 1 5 8-160. Notes on two specimens of hrowni. 30 Bulletin 12: Zoological Society of San Diego EXPLANATION OF FIGURES Fig. 1. Plyyllorhymbiis dccnrtatiis ilecurtatm, Mexican Leaf-nosed Snake. Adult male collected by Dr. Walter Mosauer at San Ignacio, Lower California, Mexico. Fig. 2. Phyllorhynchiis deciirtatiis fyerkinsi, Desert Leaf-nosed Snake. Adult male collected by L. M. Klauber at Dry Lake, San Diego County, California. Fig. 3. Phyllorhyncbm browni, Pima Leaf-nosed Snake. Adult male collected by Earl Sanders near Desert Wells, Maricopa County, Arizona. (Photograph by courtesy of FI. K. Gloyd.) Fig. 4. Everted hemipenis of P. d. pcrkitni. Klauber: The Leaf-Nosed Snake 31 Fig. 1. Fig. 2. Fig. 3. Fig. 4. 3 .. 1 I ->^- T , ■ T ,-^ 5 ; ' -’" ■:■ »*'•' ■C‘“ Km V ' ■'; r.C ■ " *4'J ra* ■rWJV sTi dif. T J 'i .if-y " h', -j -v/ffilP! r(K. *%■' ^ 5 V < I ’'1 ■ t.%- ^!j^ru ‘.rf ‘ ^ -■ a<- 'Vf r-tT^, K-. ..Si—J-'.Ma'R ' « f , / "V • if- y^>- V y f- 4 *' \A- * iri >1 * - ■ ^ '"te ■ . ff, fly <'» ‘' ' A i ,‘i . Vi- 1 .;‘- lAJ »■ i' - ♦ * Im ;} y ^ <« k I r^x.s'xi