FROGS OF COLOMBIA — COCHRAN AND GOIN 293 



above the vent. An elongate triangular area of the dark ground color 

 is present on the back; the base of the triangle, is between the eyes, and 

 the apex extends posteriorly about halfway to the sacral hump. A 

 conspicuous, light-colored area is present on dorsal surface of each 

 shank, extending from knee to tip of heel. Along the sides the dark 

 dorsal ground color merges gradually with the cadaverish gray ventral 

 color. Pigment on thigh is limited to a trace on the distal portion of 

 dorsal surface. 



Remarks. — It is impossible, on the present state of our knowledge, 

 to write an adequate discussion of the variation in Hyla leucophyllata. 

 Specimens from Leticia have the pattern that usually is considered 

 rather typical for the species — top of head and dorsum silvery white 

 with a dark rectangular figure extending from between the eyes to 

 region of the sacral hump and a large, silvery white daub completely 

 covering the dorsal surface of the shank. Specimens from Florencia 

 have the rectangular dark spot reduced to an elongate, triangular 

 spot that extends from between the eyes and has its apex reaching 

 about the middle of the back (see Fig. 31). Two specimens (MLS 

 225-6) from Ceilan, which is just west of Florencia, have the dorsal 

 dark spot completely obliterated so that the entire dorsal surfaces of 

 head, body, shanks (including both knee and heel) and fore arm are 

 white. 



Outside of Colombia, the problem of geographic distribution be- 

 comes even more complex. Specimens from southeastern Brazil seem 

 to be essentially like those from eastern Colombia, but specimens 

 from the eastern slopes of the Andes in Ecuador and Peru will have 

 to be studied in more detail than previously before a real under- 

 standing can be reached. In this region one can find fairly typical 

 examples of H. leucophyllata, individuals that match Andersson's 

 description and figure of H. bifurca, and, of course, topotypes of 

 H. sarayacuensis at Sarayacu. While bifurca superficially resembles 

 leucophyllata, it differs in that there is no connection between the 

 white above the vent and the white in the dorsolateral lines and in 

 that the white daub is absent from the dorsal surface of the shank 

 and is restricted to a tiny spot on each heel. Since one can find speci- 

 mens similar to bifurca in eastern Ecuador together with sarayacuensis 

 and leucophyllata, it seems probable that bifurca is a valid species. 



The type of Hyla frontalis is somewhat intermediate in pattern 

 between bifurca and leucophyllata. In it the white spot above the 

 vent is quite enlarged and nearly, but not quite, comes in contact 

 with the posterior end of the dorsolateral stripes in the region of the 

 sacral hump. Furthermore, the marking of the shank is intermediate, 

 for it has two rather large distinct daubs on each shank — one on the 



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