FROGS OF COLOMBIA — COCHRAN AND GOIN 509 



the webbing between the third and fourth fingers extending well 

 onto the base of the penultimate phalanx of both of these digits. 

 The choanae are small and rounded and separated from each other by 

 a distance equal to nearly three times their own diameter. The upper 

 eyelids appear whitish when viewed from above in the larger speci- 

 mens; in the small individuals they appear darker. When the hind 

 leg is extended anteriorly along the side, the heel reaches to tip of 

 the snout or beyond. The tympanum is weakly evident externally 

 and is about one-fourth the diameter of the eye and separated from 

 the base of the eyelid by about one-half its own diameter. 



The absence of vomerine teeth distinguishes Centrolenella fleisch- 

 manni from all other centrolenids known from northern South America 

 except cochranae, buckleyi, griffithsi, antioquiensis, ocellata, johnelsi, 

 and petersi. It differs from cochranae, buckleyi, and griffithsi by having 

 the web extending to the bases of the penultimate phalanges of the 

 third and fourth fingers; from antioquienois by having the dorsum 

 pale rather than heavily pigmented; from ocellata by the absence of 

 a dorsal pattern (the very dark dorsum of ocellata is marked with 

 distinct, white-centered ocelli); and from johnelsi by lacking the 

 numerous spiny wart-like protuberances on the dorsal surface. It 

 differs from petersi in the following respects: the web reaches only to 

 the penultimate phalanx of the fourth toe or does not reach it at all 

 (in petersi it extends well up onto the penultimate phalanx) ; the disk 

 of fourth toe practically covers the indistinct tympanum (in petersi 

 the digital disks are reduced, with the disk of fourth toe covering 

 only about half the distinct tympanum); and the specks of pigment 

 have no semblance of a pattern (in petersi, small circles of pigment 

 specks form weak ocelli-like marks on dorsal surfaces of back, fore- 

 arms, thighs, and shanks). 



Description. — NMS 3752 (paratype), San Jose, Costa Rica. No 

 vomerine teeth. Choanae small, rounded, separated by a distance 

 equal to about 2% times the diameter of a choana. Tongue two- 

 thirds as wide as mouth opening, rounded, its posterior border fused 

 and unnotched. Snout short, rounded when viewed from above, 

 truncate in profile, the upper jaw extending but slightly beyond 

 lower; nostrils more lateral than superior, slightly projecting, their 

 distance from end of snout nearly one-half that from eye, separated 

 from each other by an interval equal to about three-fourths their 

 distance from eye. Canthus rostralis scarcely defined; loreal region 

 concave and oblique, the upper lip flaring out appreciably below it. 

 Eye moderate in size, prominent, its diameter equal to its distance 

 from nostril; palpebral membrane not reticulare; interorbital distance 

 half again as great as width of upper eyelid, which is about equal 

 the distance between nostrils. Tympanum not very distinct, about 



