BARBOUR AND NOBLE: AMPHIBIANS FROM PERU. 421 



Diagnosis. A medium-sized frog with smooth, somewhat loose skin; with a 

 strong supratympanic fold; vomerine teeth not greatly developed, in two small 

 groups; the tibiotarsal articulation reaching nearly to the eye and having a 

 dark sooty grey ventral surface except for the throat which is conspicuously 

 pale. 



Habitat. Mountain streams of the high Andes of Central Peru. 

 Description. Adult M. C. Z. 4,790 from Tarma, Central Peru 1916; 

 John M. Boutwell. 



Size moderate; head scarcely broader than long, about equal to width of 

 body, its length contained in total length of body 3^ times; snout declivous, 

 rounded, somewhat projecting, without canthus rostralis; nostril slightly 

 nearer orbit than tip of snout. Vopierine teeth in two tiny groups, very feebly 

 developed, situated directly between and nearly touching the choanae; each 

 aperture being much larger than a group of the teeth; tongue moderate, 

 slightly longer than broad. Interorbital space very slightly wider than 

 upper eyelid; the length of the snout one and one half times that of the 

 eye; tympanum hidden. Digits free, scarcely dilated at the tips, the first 

 finger equal to the second, much shorter than the fourth; the elbow extended 

 forward reaches the center of the eye. Toes extensively webbed, but webs 

 incised to appear but half developed; a distinct tarsal fold; subarticular 

 tubercles distinct, the inner metatarsal twice as long as the outer; heels just 

 touching when the hind limbs are folded at right angles to the axis of the 

 body; the tibiotarsal articulation reaching the posterior border of the eye 

 when the hind limb is carried forward along the body. Skin above glandular, 

 smooth or slightly spiny, a well-developed dermal lateral fold from orbit to 

 groin; skin on sides of body very loose and baggy; abdominal area ill-defined 

 by folds; skin of thighs loose and baggy also. 



In the male described, there is a prominent area covered with fine asperities 

 on the chest as well as the usual digital asperities, which on the thumb are 

 extraordinarily developed. 



Color uniform slate above, faintly spotted with darker; ventral surface 

 dirty yellow washed with dusky grey; a pale area beneath each thigh; throat 

 pale, unspotted. 



Dimensions. 



Tip of snout to vent 55 mm. 



Tip of snout to angle of jaw 20 " 



Greatest width of head 21 " 



Fore leg to tip of longest finger 32 " 



Hind leg to tip of longest toe 79 " 



Remarks. This species, described by Peters, was obtained during 

 Count Jelski's journey in Peru, and the type-locality is the small 



