Part 10

Variation.--The third upper tooth-row is interrupted in all specimens, but in some individuals the first upper row and first lower row are complete. The only noted variation in color is the intensity of brown pigmentation on the caudal musculature, which in most specimens is sufficiently dense to make the tail look brown. In some specimens the mid-lateral streak is indistinct, and the pale spot below the streak is absent.

Comparisons.--Aside from the characters listed in the diagnosis, Ptychohyla schmidtorum chamulae differs from P. schmidtorum schmidtorum by having dark brown webbing on the feet, instead of pale creamy tan webbing, and in having in life a yellow venter, instead of a white venter. Ptychohyla ignicolor also is green in life, but has red flash-colors on the thighs, red webbing on the feet, and lacks the white lateral stripe diagnostic of P. schmidtorum chamulae.

Plectrohyla matudai matudai and P. guatemalensis are sympatric with Ptychohyla schmidtorum chamulae. Each of the first two has a bony prepollex, rugose skin on the dorsum, and heavy body. Also living with Ptychohyla chamulae are Hyla chaneque, a large species having a tuberculate dorsum and webbed fingers, and Hyla bivocata, a small yellow species having a broad, flat head, small indistinct tympanum, and an axillary membrane.

Life History.--Calling males were found on leaves of herbs and bushes by cascading streams in cloud forest. The call consists of series of short notes, three to nine notes per series, sounding like "raa-raa-raa." The duration of each note is .054 to .070 of a second, and has a rate of 96 to 110 pulses per second. The dominant frequency falls between 3350 and 3450 cycles per second (Pl. 11D). The call is almost indistinguishable from that of Ptychohyla schmidtorum schmidtorum.

Tadpoles were found in the cascading streams; the smallest tadpole has a total length of 17.2 mm. and has only 3/2 tooth-rows. At a stream 6.2 kilometers south of Rayon Mescalapa, Chiapas, metamorphosing young were found on June 16 and August 5, 1960. Each of two completely metamorphosed young has a snout-vent length of 15.7 mm. Another having a snout-vent length of 16.2 mm. has a tail stub 2 mm. long and a completely metamorphosed mouth. Two others have snout-vent lengths of 13.6 and 14.1 mm. and tail lengths of 11.5 and 8.1 mm. respectively; in these the mouth parts are incompletely metamorphosed.

Remarks.--Duellman (1961:354) described Ptychohyla chamulae and stated that it probably was most closely related to P. schmidtorum. Further study has revealed additional resemblance in morphological and behavioral details. It is concluded that the two populations are more realistically treated as subspecies than as species. The geographic ranges, as now known, are disjunct. Ptychohyla schmidtorum chamulae inhabits cloud forest on the Atlantic slopes of the Chiapan Highlands, whereas P. s. schmidtorum lives in cloud forest on the Pacific slopes of the Sierra Madre in Chiapas and Guatemala. Between their known geographic ranges are the pine clad Sierra Madre and Chiapan Highlands, and intervening sub-humid Grijalva Valley.

Distribution.--This species is known only from elevations between 1500 and 1700 meters on the Atlantic slopes of the Chiapan Highlands; it is to be expected in cloud forests on the northern slopes of the Sierra de Cuchumatanes in Guatemala.

Specimens examined.--MEXICO: Chiapas: 15 km. N of Pueblo Nuevo Solistahuacan, UMMZ 123325 (4); 16.5 km. N of Pueblo Nuevo Solistahuacan, UMMZ 123322 (10); 18 km. N of Pueblo Nuevo Solistahuacan, UMMZ 121395-9, 123324 (8), 123326 (5); 18.6 km. N of Pueblo Nuevo Solistahuacan, UMMZ 123323 (4); 5.6 km. S of Rayon Mescalapa, KU 58062, 58200 (tadpoles); 6.2 km. S of Rayon Mescalapa, KU 58063-74, 58199 (tadpole), 58234-8, 59936 (skeleton).

=Ptychohyla ignicolor= Duellman

Ptychohyla ignicolor Duellman, Uni. Kansas Publ. Mus. Nat. Hist., 13:352-353, pl. 25, fig. 1, April 27, 1961 [Holotype.--UMMZ 119603 from 6 kilometers south of Vista Hermosa, Oaxaca, Mexico; Thomas E. Moore collector].

Diagnosis.--Diameter of tympanum less than one-half diameter of eye; internarial region flat; 3-7 vomerine teeth; toes one-half webbed; no white spot below eye; no lateral white stripe; in life dorsum green; groin and thighs having bright red flash-colors.

Description.--The following description is based on UMMZ 119603 from 6 kilometers south of Vista Hermosa, Oaxaca, Mexico (Pl. 18). Adult male having a snout-vent length of 30.0 mm.; tibia length, 14.6 mm.; tibia length/snout-vent length, 48.7 per cent; foot length, 12.3 mm.; head length, 9.2 mm.; head length/snout-vent length, 30.7 per cent; head width, 9.3 mm.; head width/snout-vent length, 31.0 per cent; diameter of eye, 3.2 mm.; diameter of tympanum, 1.3 mm.; tympanum/eye, 40.6 per cent. Snout in lateral profile square, and in dorsal profile rounded; canthus pronounced; loreal region slightly concave; lips moderately flaring; top of head flat; nostrils protuberant; internarial distance, 2.8 mm.; internarial region flat; interorbital distance, 3.3 mm., much broader than width of eyelid, 2.8 mm. A heavy dermal fold from posterior corner of eye above tympanum to insertion of forelimb, covering upper edge of tympanum; tympanum elliptical, its greatest diameter equal to its distance from eye. Forearm moderately robust having distinct dermal fold on wrist; pollex moderately enlarged without nuptial spines; second and fourth fingers equal in length; subarticular tubercles round, none is bifid; discs on fingers moderate in size, that on third finger slightly larger than tympanum; no web between first and second fingers; vestige of web between other fingers. Heels overlap when hind limbs adpressed; tibiotarsal articulation extends to anterior corner of eye; no tarsal fold; inner metatarsal tubercle large, flat, and elliptical; outer metatarsal tubercle near inner one and triangular in shape; subarticular tubercles round; length of digits from shortest to longest 1-2-5-3-4; third toe webbed to proximal end of penultimate phalanx; fourth toe webbed to distal part of antepenultimate phalanx; fifth toe webbed to middle of penultimate phalanx; discs on toes smaller than on fingers. Anal opening directed posteriorly at upper edge of thighs; no anal flap; pair of large tubercles below anal opening; small tubercles ventral and lateral to these. Skin of dorsum and ventral surfaces of limbs smooth; that of throat and belly granular. Ventrolateral glands noticeably thickened, extending from axilla nearly to groin and only narrowly separated midventrally on chest; skin of anterior part of chin thickened and glandular. Tongue cordiform, shallowly notched behind and only slightly free posteriorly; vomerine teeth 0-3, situated on rounded elevations between somewhat larger, round inner nares; openings to vocal sac large, one situated along posterior margin of each mandibular ramus.

Dorsal ground-color of head, body, and limbs dull brown with dark brown reticulations on head and body and dark brown transverse bands or spots on limbs; first and second fingers cream color; third and fourth fingers dull tan; anterior surfaces of thighs pale brown; posterior surfaces of thighs cream color with heavy suffusion of brown; dorsal surfaces of tarsi and third, fourth, and fifth toes dull brown with dark brown spots; first and second toes creamy white; webbing on foot brown; axilla and groin cream color; flanks brown; no white stripes on edge of upper lip or on flank; faint, barely discernible tan streak above anal opening; faint creamy tan line on ventrolateral edges of tarsi; throat, belly, ventral surfaces of limbs, inner edges of tarsi, and first toes cream color; outer ventral surfaces of tarsi and other toes brown; chest and throat spotted with brown; ventrolateral and chin glands orange-brown.

In life the dorsum was uniform green (Cosse Green) becoming paler green (Bright Green-Yellow) on flanks, later changing to paler green (Javel Green) on dorsum with irregular darker green (Lettuce Green) markings and greenish yellow (Green-Yellow) on flanks; anterior and posterior surfaces of thighs, ventral surfaces of shanks, anterior surfaces of tarsi, and upper proximal surfaces of first, second, and third toes red (Coral Red); venter pale creamy yellow (Sulfur Yellow); iris pale golden color (Aniline Yellow).

Variation.--Of 13 specimens, six have a cordiform tongue; the others have an emarginate tongue. Five specimens have round subarticular tubercles beneath the fourth fingers; six specimens have a bifid tubercle on one hand, and two specimens have bifid tubercles on both hands. A round gland is present on the chin of all specimens; in some the gland is barely visible, but in others it is large and distinct. In two specimens the ventrolateral glands are weakly developed; in the others the glands are well developed and orange-tan. The white anal stripe varies from a thin line to a series of white flecks. Dark brown or black flecks are present on the throat, chest, and flanks of all specimens. In some the flecks are small and widely scattered; in others the flecks are larger and more numerous. All specimens were pale green above when calling at night; later they changed to dull green with darker green reticulations. The flash-colors on the thighs and in the groin vary from red to orange-red or brownish red.

Description of tadpole.--The following description is based on KU 71716 from Vista Hermosa, Oaxaca, Mexico (Figs. 5C and 6G). Hind limbs small; total length, 39.6 mm.; body length, 11.8 mm.; body length/total length, 29.8 per cent. Body moderately depressed, only slightly wider than deep, in dorsal profile ovoid, widest just posterior to eyes; in lateral profile snout rounded; mouth directed ventrally; eyes small, directed dorsolaterally; nostrils barely protuberant, directed anteriorly, somewhat closer to eye than snout; spiracle sinistral and posteroventrad to eye; anal tube dextral. Tail long and slender; caudal fin low and rounded posteriorly; depth of caudal musculature about one-half greatest depth of caudal fin; musculature not extending to tip of tail.

Mouth large; thin fleshy lips greatly expanded and forming large funnel-shaped disc; width of mouth about two-thirds greatest width of body; outer edge of lips having one row of small papillae; inner surface of mouth smooth; scattered large papillae forming one nearly complete row around teeth; other papillae laterally; one large papilla just above each end of first lower tooth-row; beaks moderately developed bearing long, pointed denticulations; no lateral projections on upper beak; tooth-rows 3/3, all short; second and third upper rows subequal in length; first upper row shorter; first lower row equal in length to second and third upper rows; second lower row slightly shorter; third lower row shortest.

Body creamy gray with dark brown flecks above and below; mouth colored like body; caudal musculature creamy tan; caudal fin transparent; dark brown streak on anterior third of caudal musculature; rest of tail and all of caudal fin, except anterior two-thirds of ventral fin, heavily flecked with brown; iris silvery bronze color in life.

Variation.--The only other known tadpole, which was collected with the individual described above, differs in having only two upper tooth-rows. The first upper tooth-row seems not to have developed.

Comparisons.--From P. schmidtorum chamulae and P. s. schmidtorum, P. ignicolor differs as follows: Tympanum smaller; snout more nearly square; less webbing on toes; internarial region flat instead of depressed; white lateral stripes lacking.

Ptychohyla ignicolor and several small and moderate sized hylids are sympatric. From P. ignicolor these hylids can be distinguished as follows: Hyla dendroscarta has a round snout and yellow dorsum; Hyla erythromma has a round snout, green dorsum, white flanks, and a red eye; Hyla hazelae has a tarsal fold, green dorsum, and a black line on the canthus; and Ptychohyla leonhardschultzei has a tarsal fold, brown dorsum, black and white flanks, and horny nuptial spines in breeding males.

Life History.--At Vista Hermosa, Oaxaca, males were calling on vegetation above small streams on March 30, 1959, and on June 28, 1962; males were found on vegetation overhanging a stream 6 kilometers south of Vista Hermosa on June 27 and July 3, 1962. The call consists of a series of short notes, three to thirteen notes per series, sounding like "raa-raa-raa." The duration of each note is about .08 of a second and has a rate of 123 to 129 pulses per second. The dominant frequency of notes in short series is about 2100 cycles per second, whereas the dominant frequency of notes in long series is about 3150 cycles per second (Pl. 11E).

On June 28, 1962, two tadpoles of this species were found in a quiet pool in a spring-fed rivulet at Vista Hermosa, Oaxaca. Females are unknown.

Remarks.--The absence of a tarsal fold and of nuptial spines in breeding males, the nature of the breeding call, and the form of tadpole are characters that place Ptychohyla ignicolor in the P. schmidtorum-group.

Distribution.--This species is known from only two localities at elevations of 1500 and 1850 meters in the cloud forest on the northern (Atlantic) slopes of the Sierra Madre Oriental in northern Oaxaca.

Specimens examined.--MEXICO: Oaxaca: Vista Hermosa, KU 71334, 71716 (tadpoles), UMMZ 119602; 6 km. S of Vista Hermosa, KU 71335-42, 71343 (skeleton), UMMZ 119603, 123327 (2).

DISTRIBUTION AND ECOLOGY

Geographic Distribution of the Species