and fifth toes, three free on
fourth toe (Fig. 1A and B); skin tuberculate on dorsum, less so on
flanks; skin of belly granular, that on chest and throat weakly
granular; tongue cordiform, longer than wide, free and notched behind;
vocal slits large, lateral to tongue.

[Illustration: Fig. 1. A and B.--Hand and foot of _Hyla boulengeri_
(KU 102173), x 3. C and D.--Hand and foot of _Hyla s. staufferi_x (KU
57790), x 6]

In life, dorsum tan or brown with dark spots on snout, head, and
scapular region; interorbital triangle and blotch posteriorly on dorsum
dark brown; flanks pale green; groin pale green or orange, mottled with
dark brown; thighs tan or brown above with dark transverse bars on
anterior and posterior surfaces; spaces between bars green or orange;
inner surfaces of shanks and outer surfaces of tarsi brown and orange;
foot brown above; forelimbs brown and pale green above, weakly barred;
belly creamy white with scattered brown spots; vocal sac creamy white
flecked with brown; lower jaw brown with white spots on lips (Pl. 1A).

In preservative, head and dorsum dark brown with triangular spot
between eyes; dark spots on head and scapular region and dark brown
blotch posteriorly on dorsum; flanks creamy white with brown spots;
groin creamy white mottled with dark brown; thighs brown above with
dark brown transverse bars on anterior and posterior surfaces; inner
surfaces of shanks and outer surfaces of tarsi barred with pale brown;
dorsal surface of foot mottled brown and creamy white; ventral surface
of foot and toes pale brown; forelimbs faintly barred with pale brown;
belly white with a few pale brown spots; vocal sac flecked with pale
brown; lower jaw marked with small white spots on lips.

_Variation._--Geographic variation is evident in the snout-vent length,
tibia length, and foot length, all in relation to snout-vent length,
and the relative size of the tympanum to the eye (Table 1). The largest
specimens are from the humid Pacific lowlands of Costa Rica;
individuals from the Caribbean lowlands of Costa Rica, Canal Zone, and
South America are smaller. A general trend for increase in size extends
from South America to the Pacific lowlands of Costa Rica.

Most variation in color does not seem to be correlated with geography;
color variation is nearly as great within a given population as between
separated populations. However, most specimens from Rincon de Osa,
Puntarenas Province, Costa Rica, ar