Part 4

In Central America, Hyla boulengeri can be confused only with Hyla foliamorta; the latter is restricted to central and eastern Panamá and northern Colombia. The snout of foliamorta is more pointed and protruding, and the vocal sac is darker than in boulengeri; the groin of foliamorta usually is creamy white, whereas boulengeri usually has a dark spot. The skulls differ in that boulengeri has a frontoparietal fontanelle, the prevomer is larger and elongate, anteriorly connected to the premaxillary, and posteriorly separated from the sphenethmoid by cartilage; foliamorta lacks a fontanelle, the prevomer is smaller, anteriorly separated from the premaxillary by cartilage, but connected by a bony suture to the sphenethmoid. The mating call of boulengeri differs by having shorter notes, twice as many pulses per second, a higher fundamental frequency, and more closely approximated major frequencies than does that of foliamorta.

Hyla boulengeri need not be compared in detail with the other Central American members of the Hyla rubra group, because all of them are smaller and have shorter snouts, smoother skin, and dissimilar color patterns.

Distribution.--In Central America Hyla boulengeri inhabits the forested lowlands in locally humid areas in Guanacaste Province, Costa Rica, and in the humid Golfo Dulce region of Costa Rica; it occurs on the Carribbean lowlands from central Nicaragua to South America, where it ranges to Guyana and Ecuador. The highest elevations where H. boulengeri has been found are 620 meters at Turrialba, Cartago Province, and 700 meters at Tilarán, Guanacaste Province, Costa Rica (Fig. 4).

Specimens Examined.--Costa Rica: Alajuela: 9 km N Ciudad Quesada, near La Florencia, USC 8059 (4); 18 km N Florencia, USC 2624; Laguna Monte Alegre, KU 64334; Las Playuelas, 11 km S Los Chiles, USC 7216, 7217 (2), 7219; 3 km NE Muelle del Arenal, USC 2644 (5). Cartago: Turrialba, KU 24741. Guanacaste: 7 km N Liberia, USC 8096 (2), 8138 (6); 13.6 km N Liberia, USC 8151, 8171 (2); 20.5 km S Liberia, USC 8205; Taboga, 20 km SE Las Cañas, KU 102170, USC 7166; 4 km NE Tilarán, USC 8023; 6 km NE Tilarán, USC 523 (3), 6262, 7019. Heredia: Puerto Viejo, KU 64323-7 (skeletons), 104351-3 (skeletons), 64330-3, 103592-620; 1 km NE Puerto Viejo, UMMZ 126042; 1 km S Puerto Viejo, KU 84983-4 (skeletons), 86317-22, 87774 (skeleton); 4.2 km W Puerto Viejo, KU 64329, 64328 (skeleton). Limón: Mountain Cow Creek, near Banano, KU 37031, 41067 (skeleton); 3 km S Río Tortuguero, AMNH 69057; Suretka, KU 36482-8, 36699. Puntarenas: 4.8 km S Bahía Rincón on NW side Río Rincón, USC 705; Parrita, USC 6163; 4.5 km W Rincón de Osa, KU 102177-9, 104295-6 (tadpoles); 6 km SW Rincón de Osa, KU 102171-6; 4.4 km NW Villa Neilly, USC 8003; 10.5 km WNW Villa Neilly, KU 64321. San José: 21 km WSW San Isidro el General, KU 34104-6.

Panamá: Bocas del Toro: 3.2 km W Almirante, KU 95978. Canal Zone: Barro Colorado Island, FMNH 13379; near Clayton Reservation, UIMNH 42000; 2.6 km SW Fort Kobbe, KU 95977; Miraflores Locks, AMNH 69764-5; Summit, AMNH 73445, KU 97777, 101540-9, 104350 (skeleton). Colón: Río Gatuncillo, near Nuevo San Juan, KU 95976. Darién: El Real, KU 80451-3.

Hyla foliamorta Fouquette

Hyla foliamorta Fouquette, Herpetologica, 14:125, April 25, 1958 [Holotype.--TNHC 23109, 11 km. NW Miraflores Locks, Canal Zone, Panamá; M. J. Fouquette, Jr. collector].

Diagnosis.--Size medium (Male to 43 mm., Female to 41 mm.); skull longer than wide; frontoparietal fontanelle absent; snout acuminate, projecting; interorbital triangle bordered by white lines; scapular region having two or more elongate spots; dorsum smooth; vocal sac dark gray; groin creamy white; traces of web between fingers.

Description.--Head flattened, longer than wide; snout flat, pointed, protruding beyond lower lip; loreal region slightly concave; canthus moderately prominent; eyes smaller than interorbital space; tympanum distinct, 55 to 75 per cent of diameter of eye, smaller than internarial space; arms short; fingers having rudimentary webs; median palmar tubercle tripartite; inner palmar tubercle on base of first finger flat; subarticular tubercles distinct; discs of fingers smaller than diameter of tympanum; legs long; tarsal fold lacking; inner metatarsal tubercle larger than outer; one phalanx free on second, third, and fifth toes, two and one half phalanges free on fourth toe; narrow fringe continuing from web to discs of toes; discs of toes about the size of those on fingers; skin smooth on dorsum and flanks, that on belly and posterior part of thighs granular; tongue oval, longer than wide; vocal slits oblique, about one half length of tongue.

In life, dorsum pale tan to pale reddish brown with irregular reddish brown markings; small dark spots on head; distinct dark brown triangular mark between eyes, bordered by thin white lines; apex of triangle always directed backward; supratympanic fold with black edge; scapular region having two to five small, elongate black spots; belly creamy tan with small brown spots; vocal sac uniformly dark brown with scattered creamy tan flecks; upper jaw dark brown; limbs creamy white below with scattered brown spots; groin marked with small brown spots in some specimens; anterior and posterior surfaces of thighs yellow-orange with three distinct black blotches; two dark bands on upper surface of shanks; webbing of feet yellowish tan with brown mottlings (Pl. 1B).

In preservative, dorsum brown or gray with darker markings; interorbital triangle distinct, bordered by white lines; supratympanic fold with black edge; two or more small elongate black spots in scapular region; belly white with numerous brown flecks; edge of upper lip dark brown; vocal sac dark gray; undersides of limbs creamy white; groin creamy white with or without brown spots; anterior and posterior surfaces of thighs having three black blotches separated by creamy white spaces; shanks having two brown bands; webbing of feet mottled with brown.

Variation.--Twenty-eight breeding males from the area between Chepo and Tocumen, Panamá, have snout-vent lengths of 39.0 mm. to 46.0 mm. (mean 42.5 mm.). In these specimens, the ratio of the tibia length to the snout-vent length is 0.54 to 0.61 (mean, 0.57); the ratio of the diameter of the tympanum to that of the eye is 0.55 to 0.75 (mean, 0.67). One female has a snout-vent length of 41.0 mm., tibia/snout-vent length ratio of 0.57, and tympanum/eye ratio of 0.76. Two to five (usually three) elongate black spots are present in the scapular region in different individuals. The flanks in some are spotted with brown; in others they are creamy white. A small black spot is present in the groin of some specimens. Usually two to four blotches are present on the anterior and posterior surfaces of the thighs; in some specimens the blotches are reduced to small spots. One or two brown spots are present proximally on the shanks in most specimens. In some individuals tuberculations are scattered on the head and in the tympanic and scapular regions, but the dorsum is smooth in most specimens; the belly is creamy white flecked with brown.

Cranial Osteology.--The skull of Hyla foliamorta is flat and longer than it is wide. The premaxillary is small and bears 13 to 16 teeth (mean for 2 specimens, 14.8). The alary process of the premaxillary is vertical and concave posteriorly. Ventrally, the premaxillary is completely separated from the prevomer by cartilage. The maxillary is slender; each bears 77 to 84 teeth (mean for 2 specimens, 81). The pars facialis of the maxillary is laterally convex and less than three times the height of the pars dentalis.

The nasal is large and pointed anteriorly and posteriorly in dorsal view. The length of the nasal comprises about 40 per cent of the total length of the skull. The nasals are separated anteromedially by the cartilaginous septum nasi. One protuberance is present on the midlateral concavity of the nasal. Posteriorly, the nasal overlaps the sphenethmoid; posterolaterally the nasal articulates with the palatine. The sphenethmoid is completely ossified and pentagonal in dorsal view. The frontoparietal is elongate, without a pronounced anterior supraorbital process. The frontoparientals are sutured medially throughout their lengths; the frontoparietal fontanelle is absent.

The bony part of the proötic is narrowly separated dorsolaterally from the squamosal by the cartilaginous crista parotica. The squamosal is large; the anterior arm is pointed. The posterior arm of the squamosal is broad, rounded terminally, and articulates with the proötic medially.

The prevomer is short and separated anteriorly from the premaxillary and maxillary by cartilage. The posterior margin of the prevomer has a bony articulation with the sphenethmoid. Each prevomer bears five to seven teeth. The palatine is small and edentate. The anterior end of the parasphenoid is narrow (more pointed than in Hyla boulengeri). The pterygoid is slender and well developed (Fig. 5A).

Natural History.--Hyla foliamorta inhabits lowland forests in eastern Panamá and breeds in temporary ponds. Males have been observed calling from grasses, bushes, and emergent vegetation near temporary ponds and ditches along roads. William E. Duellman informed me that he found a breeding congregation of this species in June near Chepo, Panamá, where males were calling from spiny palms at the edge of a woodland pond. Fouquette (1958) found calling males in May, August, and September near Miraflores Locks, Canal Zone. Calling stations vary from one to two meters above ground. No clasping pairs have been found; only one female is known (KU 101589, from 8 km NE Tocumen, Panamá); this gravid individual was collected in early June.

The mating call of Hyla foliamorta consists of one pulsed, low-pitched, moderate trill of about O.5 second duration. Each note is repeated at intervals of 5 seconds to a few minutes. The notes have about 50 pulses per second, a fundamental frequency of 56 cycles per second and a dominant frequency of about 3000 cycles per second (Table 2, Pl. 3B).

Egg deposition sites are unknown. No information is available concerning early development, and little is known about the breeding season of Hyla foliamorta. Probably its breeding activities are restricted to the rainy months.

Tadpoles.--Eight tadpoles were collected from a weedy temporary pond near Chepo, Panamá, in early June.

A typical tadpole in stage 35 of development (KU 104244) has a body length of 9.5 mm., tail length of 25.0 mm., and a total length of 34.5 mm. Other characters are as follows: depth of tail equal to length of body; body deeper than wide; distance between eye and nostril equal to distance between eye and spiracle; mouth anteroventral; median part of upper lip bare; rest of lip having one row of papillae; a few other rows of small papillae at corners of mouth; tooth rows 2/3; first upper row entire, second upper row interrupted medially, shorter than first; lower rows shorter than upper rows, third shortest; beak moderately robust; spiracle nearer eye than anus; anal tube short, aperture not extending to border of ventral fin; caudal musculature slender, extending to tip of pointed tail; dorsal fin extending onto body (Table 4).

TABLE 4.--Sizes of Tadpoles of Hyla foliamorta in Relation to Developmental Stages. (Means in parentheses below observed ranges; measurements in mm.)

======================================================= Stage | N | Body length | Tail length | Total length --------+---+-------------+-------------+-------------- 25 | 2 | 5.0-5.2 | 8.0-8.5 | 13.0-13.7 | | (5.1) | (8.3) | (13.4) | | | | 26 | 3 | 7.0-7.5 | 12.0-12.4 | 17.0-19.5 | | (7.2) | (12.1) | (18.6) | | | | 28 | 2 | 6.5-7.0 | 18.0 | 25.0 | | (6.8) | | | | | | 35 | 1 | 9.5 | 25.0 | 34.5

In life, yellow above, white below; caudal fin greenish yellow with black or gray reticulations; dark line from snout to eye; dark spot behind eye; tail unpigmented except for fine dark reticulations. In preservative body creamy white, transparent below with dark pigment above in some specimens.

Remarks.--Hyla foliamorta can be confused only with Hyla boulengeri. The differences between adults of these species were discussed in Remarks on H. boulengeri. The tadpoles of foliamorta have labial papillae on the lower lip and a stripe between the eye and the tip of the snout. By comparison the tadpoles of boulengeri have a bare lower lip and no stripe between the eye and the tip of the snout.

Distribution.--Hyla foliamorta inhabits the subhumid Pacific lowlands (elevations of less than 100 meters) of Central Panamá and Caribbean lowlands of northern Colombia (Fig. 4).

Specimens Examined.--Panamá: Panamá: 3 km WSW Chepo, KU 77164-9, 101573-5, 104243-4 (tadpoles); 6 km WSW Chepo, KU 77170, 101576-8; 1.5 km SW Naranjal, KU 77171, 77687 (skeleton); 2 km N Tocumen, KU 101579-83, 104349 (skeleton); 8 km NE Tocumen, KU 101584-92.

No specific locality: TNHC 24401.