282 U.S. NATIONAL MUSEUM BULLETIN 2 88 



eye, separated from eye by a distance equal to one-half its own 

 diameter. Fingers webbed at base, web on third finger reaching middle 

 of antepenultimate phalanx on lateral side and the base of ante- 

 penultimate phalanx on medial side, fourth finger considerably longer 

 than second, reaching to disk of third which just covers the tympanic 

 area; no projecting rudiment of a poll ex; no ulnar ridge. Toes more 

 than one-half webbed, the web on fourth toe reaching base of pen- 

 ultimate phalanx, third and fifth toes subequal, disk of fourth toe 

 practically covering the tympanic area; a distinct oval inner and a 

 smaller but equally distinct rounded outer metatarsal tubercle; no 

 outer but a low inner tarsal ridge; no dermal appendage on heel. 

 Body not elongate, in postaxillary region a little narrower than great- 

 est width of head; when hind leg is adpressed, heel reaches almost 

 to tip of snout; when limbs are laid along the side, knee and elbow 

 overlap considerably; when hind legs are bent at right angles to 

 body, heels overlap greatly. A patagium extends from the back of 

 the upper arm to the side of the body. Skin of upper parts smooth; 

 a low, rather narrow glandular ridge passes above the tympanum; 

 skin of throat and chest smooth, that of belly and lower surface of 

 thigh uniformly and finely granular; traces of a skinfold across chest; 

 adult male, vocal sac subgular, thin, and heavily folded. Skin of head 

 not co-ossified with skull, roof of skull not exostosed. 



Dimensions. — Head and body, 23.6 mm.; head length, 7.5 mm.; 

 head width, 7.5 mm.; femur, 11.8 mm.; tibia, 12.3 mm.; heel-to-toe, 

 17 mm.; hand, 6.4 mm. 



Color in alcohol. — A pale creamy yellow with longitudinal stripes on 

 the dorsum. A median pair of pale brown stripes originate on inner 

 margin of upper eyelids, and each stripe continues back to above 

 the tip of urostyle. The sides of the body are slightly darker than the 

 dorsum, and the pigmentation where the dorsal and lateral side 

 colors meet forms brownish stripes that originate at the posterior 

 corners of the eyes, pass above the tympani, and extend along the 

 sides nearly to the groins. The thighs are immaculate but there are 

 scattered pigment cells on top of arms, shanks, and feet. The ventral 

 surfaces are immaculate. 



Variation. — We can discern geographic variation worthy of note in 

 the Colombian specimens of this species. For example, the specimens 

 from around the Fundaci6n-Aracataca region in Magdalena diverge 

 from the typical pattern of Hyla microcephala (which consists of four 

 longitudinal dark stripes) as follows: A narrow dark stripe originates 

 on the tip of the snout and passes posteriorly through the eye on each 

 side and then passes straight back above the tympanum and shoulder 

 to terminate in the region of the groin. Another pair of stripes originate 

 between the eyes and pass directly posteriorly, being separated by a 



