A Review of the Middle American Tree Frogs of the Genus Ptychohyla Part 6

chamulae_.

_Ptychohyla schmidtorum schmidtorum_ and several species of _Plectrohyla_ are sympatric. All species of the latter genus have a bony prepollex, rugose skin on the dorsum, and heavy body; also sympatric is _Ptychohyla e. euthysanota_, which has a tarsal fold and in breeding males spinous nuptial tuberosities.

_Life History._--This species breeds in clear mountain streams where males call from vegetation along the stream. 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 approximately .065 of a second, and has a rate of 96 to 119 pulses per second; the dominant frequency is about 3400 cycles per second. The call is almost indistinguishable from that of _Ptychohyla schmidtorum chamulae_.

Tadpoles and metamorphosing young were found at Finca La Paz, Guatemala, in late July, 1960. Two young lacking tails but not having completely developed mouths have snout-vent lengths of 14.2 and 14.6 mm. L. C. Stuart collected four metamorphosing young at Finca La Paz on May 6, 1949. By May 10 the frogs were completely metamorphosed, at which time they had snout-vent lengths of 15.5 to 17.0 (average 16.1) mm.

_Remarks._--There is no doubt that this frog is most closely related to _Ptychohyla schmidtorum chamulae_, even though the ranges of the two subspecies are separated by the interior depression of Chiapas.

Since at least at Finca La Paz, Guatemala, _P. s. schmidtorum_ occurs with _P. e. euthysanota_, it is surprising that the former species has not been found at more localities along the Pacific slopes on northern Central America. At Finca La Paz in July, 1960, _P. s. schmidtorum_ was more abundant than _P. e. euthysanota_.

_Distribution._--This species is known only from a limited area at elevations between 1300 and 2200 meters on the Pacific slopes of the Sierra Madre in extreme eastern Chiapas and western Guatemala.

_Specimens examined._--MEXICO: _Chiapas_: Finca Irlandia, UMMZ 105429-30.

GUATEMALA: _San Marcos_: El Porvenir, CNHM 20755, 20761, 69904, UMMZ 80918; Finca La Paz, 2 km. W of La Reforma, KU 58016-44, 59940-2 (skeletons), 60050 (3 young), 60051 (tadpoles), 60052 (4 young), MCZ 34998-9, UMMZ 123144-7 (tadpoles).

[Ill.u.s.tration: PLATE 17 _Ptychohyla schmidtorum chamulae_ (KU 58069). 2.]

=Ptychohyla schmidtorum chamulae= Duellman

_Ptychohyla chamulae_ Duellman, Univ. Kansas Publ. Mus. Nat. Hist., 13: 354-357, pl. 25, fig. 2, April 27, 1961 [Holotype.--KU 58063 from 6.2 kilometers south of Rayon Mescalapa, Chiapas, Mexico; William E. Duellman collector].

_Diagnosis._--Vomerine teeth 4-6; dorsum bright green; white lateral stripe; eye reddish bronze in life.

_Description._--The following description is based on KU 58069 from 6.2 kilometers south of Rayon Mescalapa, Chiapas, Mexico (Pl. 17).

Adult male having a snout-vent length of 27.6 mm.; tibia length, 13.0 mm.; tibia length/snout-vent length, 47.1 per cent; foot length, 10.8 mm.; head length, 9.6 mm.; head length/snout-vent length, 34.7 per cent; head width, 9.2 mm.; head width/snout-vent length, 33.1 per cent; diameter of eye, 3.0 mm.; diameter of tympanum, 1.6 mm.; tympanum/eye, 53.3 per cent. Snout in lateral profile nearly square, slightly rounded above and below, and in dorsal profile blunt, almost square; canthus p.r.o.nounced; loreal region concave; lips thick, rounded and flaring; nostrils protuberant; internarial distance, 2.5 mm.; internarial region slightly depressed; top of head flat; interorbital distance, 3.3 mm., much greater than width of eyelid, 2.5 mm. Thin dermal fold, from posterior corner of eye above tympanum to insertion of fore limb, covering upper edge of tympanum; tympanum nearly round, its diameter equal to its distance from eye. Forearm slender, lacking distinct fold on wrist; row of low, rounded tubercles on ventrolateral surface of forearm; pollex slightly enlarged, without nuptial spines; second and fourth fingers equal in length; subarticular tubercles round, that under fourth finger bifid; discs small, that of third finger noticeably smaller than tympanum; no web between first and second fingers; vestige of web between other fingers. Heels overlapping when hind limbs adpressed; tibiotarsal articulation reaches to middle of eye; no tarsal fold; inner metatarsal tubercle large, flat, and elliptical; outer metatarsal tubercle small, elliptical, slightly more distal than inner; subarticular tubercles round; length of digits from shortest to longest 1-2-5-3-4; third and fifth toes webbed to base of disc; fourth toe webbed to base of penultimate phalanx; discs smaller on toes than on fingers. a.n.a.l opening directed posteriorly at upper edge of thighs; no a.n.a.l flap; pair of large tubercles below a.n.a.l opening. Skin of dorsum and of ventral surfaces of forelimbs and shanks smooth; that of throat, belly, and ventral surfaces of thighs granular. Ventrolateral glands well developed, not reaching axilla or groin and broadly separated midventrally. Tongue cordiform, shallowly notched behind and only slightly free posteriorly; vomerine teeth 2-3, situated on small triangular elevations between ovoid inner nares; openings to vocal sac large, one situated along inner posterior edge of each mandibular ramus.

Dorsum of head, body and limbs reddish brown with dark purplish brown markings on back and shanks; first finger creamy tan; other fingers pale brown; dorsal surfaces of tarsi, third, fourth, and fifth toes dull tan with brown spots; first and second toes creamy tan; webbing on feet brown; anterior and posterior surfaces of thighs tan; faint creamy white stripe along ventrolateral edges of tarsi and forearms; enamel-white stripe on heel; axilla and groin gray; enamel-white stripe on edge of upper lip, continuing onto proximal upper surfaces of forelimb and on flanks to groin, widened under eye to form large spot, and bordered below on flanks by dark brown stripe; white stripe above and white spots below a.n.a.l opening; throat and chest white; belly and ventral surfaces of limbs cream color; brown dash on either side of chin and brown spot on throat near angle of jaws; few brown flecks on belly; ventrolateral glands orange-tan; ventral surfaces of tarsi and feet brown.

In life, dorsal surfaces of head, body, and limbs bright green (Shamrock Green); first and second fingers pale orange (Apricot Yellow); stripe on upper lip and spot below eye enamel-white; stripe on flanks silvery white, bordered below by brown (Saccardo's Umber) brown; anterior and posterior surfaces of thighs yellowish brown (Old Gold); webbing of feet dull brown (Brownish Olive); belly deep yellow (Amber Yellow); iris reddish bronze (English Red).

_Variation._--Tubercles beneath the fourth fingers are bifid in 20 specimens and rounded in all others. The tongue is emarginate in 12 specimens and cordiform in all others. In most specimens the white stripe on the upper lip continues onto the flanks and to the groin; in five specimens the stripe terminates above the forearm, and in three it terminates at mid-flank. The lateral stripe is absent in two specimens. All specimens were uniform green above when found at night; later some changed to pale green (Light Oriental Green) on the dorsum with irregular yellowish tan (Naples Yellow) blotches. Most males have brown flecks on the throat and ventrolateral gland, but some specimens are immaculate below, and one has dark brown mottling on the throat.

Several males have a round, orange-tan glandular area on the chin, as does _P. ignicolor_.

_Description of tadpole._--The following description is based on KU 58199 from 6.2 kilometers south of Rayon Mescalapa, Chiapas, Mexico (Figs. 5B and 6F). Hind limbs small; total length, 39.0 mm.; body length, 10.5 mm.; body length/total length, 26.9 per cent. Body barely depressed, only slightly wider than deep, widest just posterior to eyes; in dorsal profile ovoid; mouth directed ventrally; eyes small, directed dorsolaterally; nostrils barely protuberant, directed anterodorsally, slightly closer to eye than snout; spiracle sinistral and posteroventrad to eye; a.n.a.l tube dextral. Tail long and slender; caudal fin low, rounded posteriorly; depth of caudal musculature one-half greatest depth of caudal fin; musculature not extending to tip of tail.

Mouth large; thin fleshy lips greatly expanded and forming funnel-shaped disc; outer edge of lips having one row of small papillae; inner surfaces of mouth smooth; scattered large papillae forming nearly one complete row around teeth; other papillae laterally; 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 and third upper rows interrupted medially; first lower row interrupted medially, equal in length to second and third upper rows; second lower row slightly shorter; third lower row shortest.

Body dark brown above and dark gray below; fleshy part of mouth creamy gray mottled with dark brown; caudal musculature pale tan with heavy suffusion of brown flecks; caudal fin transparent with brown spots; dark brown streak mid-laterally on anterior one-fifth of caudal musculature, bordered below by cream-colored spot; eye brown in life.

_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).

[Ill.u.s.tration: PLATE 18 _Ptychohyla ignicolor_ (UMMZ 119603). 2.]

=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 p.r.o.nounced; 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.

a.n.a.l opening directed posteriorly at upper edge of thighs; no a.n.a.l flap; pair of large tubercles below a.n.a.l 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 a.n.a.l 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 a.n.a.l 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; a.n.a.l 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 h.o.r.n.y nuptial spines in breeding males.