On a neiu Cijprinodontid Fish. 153 



with incomplete intermediate ones. Blackish, speckled with 

 yellowish on the sides. 



Total length 1170 millim.; greatest diameter of body 13. 



A single specimen from Villeta, Colombia, altitude 3503 

 feet, collected by Mr. Kay Thompson. 



This species is allied to C. gracilis, Shaw, but differs in 

 the larger teeth and in the lower position of the tentacle. 



Rhinatrema peruvianum. 



Teeth small ; both rows of mandibular teeth well developed. 

 Snout rounded, scarcely prominent, a little shorter than the 

 distance between the eyes, which are distinguishable. Body 

 rather strongly depressed, with 379 very distinct complete 

 circular folds, 28 of which are on the tail. Anal opening 

 longitudinal. Tail strongly compressed, rounded at the end, 

 a little longer than the head. Uniform dark brown, anal 

 region whitish. 



Total length 280 millim. ; greatest diameter of body 12. 



A single specimen from the Marcapata Valley, E. Peru, 

 collected by Mr. G. Ockendeu. 



This species is intermediate between R. bivitfatum, Cuv., 

 from Cayenne, and R. hicolor, Blgr., from Colombia and 

 Ecuador. It differs from the first in the longer compressed 

 tail *, from the second in the more obtuse tail and the more 

 numerous annuli on the body, from both in the absence of a 

 yellow lateral band. 



XX. — Description of a new Cyprinodontid Fish from 

 Eastern Peru. )iy G. A. Boulenger, F.R.S. 



Orestias tirapatce. 



Body compressed, its depth equal to the length of the head, 

 which is 3f to 4 times in the total length. Width of head 

 equal to its depth ; crown slightly convex ; snout obtuse, as 

 long as the eye ; mouth small, cleft to the level of the lower 

 border of the eye ; lower jaw not projecting beyond the 

 upper ; teeth very small ; eye supero-lateral, its diameter 3f 

 to 4 times in length of head, 1^ to 1^ in interocular width ; 

 scales on head imbedded in the skin, which shows very 



* My collea;/iie Dr. F. MocqiiarJ, of the Paris Museum, has kindly 

 supplied rue -with the followini>- n;easiirements of the type specimen : — • 

 Head (to occiput) 9 millim. ; leng-tli of tail 2 ; vertical diameter of tail 

 (at base) 2-75; horizontal diameter of tail (at base) ."3-o. 



