ellowish 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 Rio Claro near its junction
with the Rio 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 Rio 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_ Guenther in the highlands of Costa Rica. Both have the
same kind of, and variation in, dorsal markings; conical, pigmented
supernumerary tubercles on the