situated on transverse ridges between posterior borders of small round choanae. Vocal slit extending from midlateral edge of tongue to angle of jaw.

Color (in preservative): dorsum grayish tan with large brown blotch extending from eyelids to middle of back, limbs marked with brown transverse bars, 2 on each forearm, 3 on each thigh, shank, and foot. Flanks dark gray with white spots; groin, anterior and posterior surfaces of thighs, ventral surfaces of shanks, and inner edges of feet orange-tan; anal region dark brown, bordered above by white stripe; belly and chin creamy white, latter with grayish brown flecks.

Color (in life): dorsum yellowish tan with olive-brown markings by night and uniform pale yellowish tan by day; axilla, inner surface of elbow, groin, anterior and posterior surfaces of thighs, ventral surfaces of thighs and shanks, inner surfaces of feet, and dorsal surfaces of first three toes tomato red; flanks dark blue with yellow spots and reticulations. Throat, chest, and anterior part of belly creamy white; posterior part of belly orange, becoming red in extreme posterior region; throat flecked with brown; iris pale bronze with black reticulations; palpebral membrane clear above, yellowish tan below; nuptial excrescenses dark brown.

Variation.—The discussion of variation is based on the type series plus 31 specimens (KU 101781-811) from the Río Claro near its junction with the Río Changena, at an elevation of 910 meters. Females are slightly larger than males, but do not differ significantly in proportions (Table 1). All specimens have the diagnostic red legs and blue flanks with yellow spots or mottling, but the dorsal pattern is highly variable. In most individuals the dark markings on the dorsum are a solid color, but in some the borders of the marks are dark, and the interior of each mark is nearly the same color as the rest of the dorsum. A triangular dark mark with the anterolateral corners on the eyelids is present in all specimens. In some individuals the posteriorly directed apex of this triangular mark is connected to the apex of another triangular mark on the back; in other individuals the marks are narrowly separated, whereas in a few specimens the marks are broadly connected. A dark blotch usually is present on the posterior end of the body. One specimen (KU 101771) has many small white spots on the dorsum. The white stripe above the anus is invariably present, and the transverse bars on the limbs are present in all specimens, although they are indistinct in some individuals. The pattern on the flanks varies from three or four large spots to many (30-44) small spots. All males have dark flecks or reticulations on the throat; in some individuals the chest and belly are heavily flecked. Although the amount of flecking is much less in most females, one individual is as heavily flecked on the throat and belly as any male.

The change in coloration in this frog is noteworthy. The following description of metachrosis in seven specimens from the Río Claro illustrates the change. At night the frogs were yellowish tan above with slightly darker dorsal markings. The axilla, groin, anterior and posterior surfaces of the thighs, ventral surfaces of the hind limbs, and webbing on the hands and feet were tomato red. By day, some individuals became creamy yellow, others ashy white, and others grayish tan. The flanks were dark blue with yellow spots.

Comparisons.—The population of frogs described here closely resembles Hyla pseudopuma Günther in the highlands of Costa Rica. Both have the same kind of, and variation in, dorsal markings; conical, pigmented supernumerary tubercles on the toes; bilobate vocal sac; and large prepollex bearing horny nuptial spinules. Although at present no evidence for intergradation exists, the population described here is considered to be a subspecies of Hyla pseudopuma.

Table 1.—Variation in Certain Measurements and Proportions in the
Subspecies of Hyla pseudopuma. (Means Are Given in Parentheses Below the
Observed Range.)

The two subspecies exhibit few differences in size and proportions, except that the tympanum is larger in pseudopuma (Table 1). Hyla p. pseudopuma has dark brown or yellowish tan thighs and brown flanks with a few creamy white spots; the groin in some specimens is pale blue. The red color on the limbs characteristic of infucata is lacking in pseudopuma, which also lacks the white stripe above the anus characteristic of infucata. The only noticeable morphological difference between the subspecies, except in the size of the tympanum, is the shape of the snout. In infucata the snout is bluntly rounded in lateral profile and truncate in dorsal profile, whereas in pseudopuma the snout is more acutely rounded in lateral profile and acuminate in dorsal profile (Fig. 1). This external difference is correlated with the nature of the underlying premaxillaries. In infucata the premaxillaries lie in a transverse plane and have short, nearly vertical alary processes, whereas in pseudopuma the premaxillaries lie at a slight angle and have longer alary processes that are inclined posteriorly.

Fig. 1. Lateral views of the heads of Hyla pseudopuma pseudopuma (left, KU 64884)
and H. p. infucata (right, KU 101784). × 4.

The only other frog in Central America having red webs and anterior and posterior surfaces of the thighs is Hyla loquax, which has a broad head, extensive axillary membrane, single median vocal sac, and uniformly creamy yellow flanks; furthermore, loquax lacks conical, pigmented supernumerary tubercles on the toes and a large prepollex with horny nuptial spinules. Hyla rufitela has red webbing, but in no other diagnostic feature resembles infucata, for rufitela is green above, white below, and has angular prevomerine dentigerous