FROGS OF COLOMBIA — COCHRAN AND COIN 103 



Dimensions. — Head and body, 68 mm.; head length, 22.5 mm.; 

 head width, 26 mm.; femur, 26 mm.; tibia, 26 mm.; foot, 20.5 mm.; 

 hand, 16 mm. 



Color in alcohol. — Dorsum vandyke to seal brown, except for a few 

 indistinct clove brown spots on back and slightly darker edges on the 

 crests; side of body drab below, merging gradually with the darker 

 brown of the upper surfaces; side of head light drab, immaculate; 

 posterior surface of femur hair brown, the tubercles lighter; venter 

 light drab-gray with some large irregular drab spots on the belly, and 

 very pale suffusions of light drab on chest and throat; soles of feet 

 vandyke brown, the webs and disks a little lighter; palms of hands 

 light drab, the tubercles and disks fawn color. 



Remarks. — The smaller toads from Puerto Narino, Amazonas, are 

 more brightly marked, USNM 146827 (46.5 mm. in length) having a 

 wide pale middorsal stripe and showing two wide dark crossbands 

 across femur, tibia, foot, and forearm. The lower surface of the tarsus 

 and outer part of the metatarsal region are vandyke brown, while the 

 inner part is a contrasting pale olive-buff. One of the old males 

 (USNM 146823) has two black lunar markings between the eyes and 

 three other pairs of such markings on each side of the midline of the 

 back. The belly may be heavily brown-spotted, as in USNM 146830, 

 or nearly uniform olive-buff, as in USNM 146828, only slightly so 

 in three of the others, and quite distinctly so in the remaining three 

 specimens of the series. The knob at the angle of the jaw is produced 

 to varying degrees in all, while the "buttons" along the backbone are 

 evident in four of the specimens in the series. In fact, the knob is 

 very distinct in more than three-fourths of the toads at hand from 

 various regions in Colombia. For instance, the knob is well devel- 

 oped in 26 of 30 examples from Amazonas and 14 of 16 examples 

 from Meta. 



The toes are one-third to one-half webbed in all Colombian toads 

 examined. 



The males at breeding time have the area on the inside of the first 

 finger roughened; they can be distinguished, externally, from the 

 females even in a melanistic population. 



One of the most peculiar characteristics of this toad, aside from the 

 hyperdevelopment of the head crests, is the appearance of a row of 

 five to seven "buttons" on the midline of the back coinciding with the 

 upper central part of the seven vertebrae. This characteristic occurs 

 in its most extreme form in old males with large head crests. An ex- 

 ample from the Maroni River, British Guiana (USNM 108987, 

 figured by Cochran, 1961a, p. 42), has five large and two small "but- 

 tons" and otherwise is similar to the one from Colombia described 

 above. The protrusion of ribs through the skin is known in a few 



