276 U.S. NATIONAL MUSEUM BULLETIN 288 



below it. Eye moderate but rather prominent, its diameter greater 

 than its distance from nostril; palpebral membrane not reticulate; 

 interorbital distance about equal to width of upper eyelid, which is 

 in turn about equal the distance between nostrils. Tympanum small 

 but distinct, about one-fourth the diameter of eye, separated from 

 eye by a distance equal to about one-half its own diameter. Fingers 

 webbed at base, the web reaching to distal end of antepenultimate 

 phalanx of third finger; fourth finger slightly longer than second, just 

 reaching to disk of third which is slightly greater than the tympanic 

 area; no projecting rudiment of a pollex; no ulnar ridge. Toes slightly 

 more than one-half webbed, the web on fourth toe reaching the distal 

 end of antepenultimate phalanx; fourth toe about twice as wide 

 at base as other toes; third and fifth toes subequal, disk of fourth 

 toe just covering the tympanic area; a distinct oval inner and a smaller 

 indistinct rounded outer metatarsal tubercle; no tarsal ridge; no dermal 

 appendage on heel. Body not elongate, in postaxillary region a little 

 narrower than greatest width of head; when hind leg is adpressed, 

 heel reaches to between eye and nostril; 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 very weakly developed 

 patagium extends from the back of upper arm to side of body. Skin 

 of upper parts smooth; a rather narrow glandular ridge encircling upper 

 part of tympanum; skin of throat and chest smooth, that of belly and 

 lower surface of thigh uniformly and very finely granular; no apparent 

 traces of a skinfold across chest; adult male, vocal sac large, median, 

 subgular. Skin of head not co-ossified with skull, roof of skull not 

 exostosed. 



Dimensions. — Head and body length, 21 mm.; head length, 7.7 

 mm.; head width, 7.3 mm.; femur, 9 mm.; tibia, 11.2 mm.; heel-to- 

 toe, 15.2 mm.; hand, 6.7 mm. 



Color in alcohol. — A pale, very light brown frog. The pattern consists 

 of narrow, dark brown pencil-like lines on the dorsum. One such line 

 forms an interocular bar. A rather distinct cruciform mark on the 

 back extends from just behind each eye to a point just anterior to 

 the sacral hump on each side. There are very faint traces of darker 

 crossbars on the shanks. Other than these marks, no pattern is discern- 

 ible. The venter, like the dorsum, is a very light tannish brown. 



Variation. — Except for the degree of fading, the five specimens 

 from Colombia before us are rather uniform. Two males (CNHM 

 81856; MLS 119) seem to have brighter markings than the females, 

 but this may be due to differences in preservation. When the male 

 from the Maracaibo Basin is compared with the one from the Pacific 

 drainage, no discernible significant variation can be noted. 



