168 Evermann and RadcUffe — A Cyprinodont from Peru. 



Lake Angascancha Specimens. 



Lalcf' Tiflcaca Specimeiis. 



n 



12 



7.0 

 6.7 



...56 

 ;.37 



31 

 .32 



La Fundiciun Specimens. 



U. S. Nat. Mus. Spec. No. 53,516, from Bolivia. 



18 



15 



15 



34 



Tlie scales in the lartie.st.speciinoiis are large, convex, horny and .-smooth 

 anteriorly, becoming smaller, flattened and finely striate posteriorly; those 

 above pectoral and on sides and toj) of head are polished; those on side.s 

 of caudal peduncle more or less deciduous in some specimens; breast and 

 belly naked; top of snout and an area around eye, more or less scaleless. 

 Scales in transverse series 14 or 15 ; 20 on median line of l>ack between 

 nape and origin of dorsal; those on cheek arranged in ?> or 4 rows. In 

 young individuals, tlie scale.'^ are all very thin, finely striate and not 

 polished. 



Head and slioulders broad, heavy and archc(l in adults, nuich more 

 comi)ressed in the young; mouth small, nearly vertical ; cleft of mouth 

 extending to lower level of orbit. This character is subject to consider- 

 al)le variation ; in adults it may reach a considera])le distance below level 

 of orbit. Jaws with two series of small, simple, conical, hooked teeth; 

 those in the inner row fewer and smaller; in young examples often none 

 or only one or two of the inner series visible. 



Origin of dorsal in advance of anal, slightly nearer caudal than base of 

 occiput, situated at distance equal to its base from caudal; caudal trun- 

 cate or slightly rounded ; ventrals absent. 



Color in spirits: 20 specimens o.o to 10.1 cms. long, from Lake Angas- 

 cancha and 10 specimens, o.O to 7.6 cms. long, from La Fundicion, are 

 dusky olive on back and sides; ventral surface wiiitc or yellowish-white, 

 the duskiness of the sides encroaching on this area in tlieolder examples; 

 in some specimens some of the scales on sides, especially on the head 



