150 THE CYPRINODONTS. 



oblique as in 0. Cuvieri, but intermediate in size between that species and 

 0. Pentlaiidii. Tongue with papillae resembling small teeth. Eyes large, orbit 

 extending above level of crown, longer than snout, little less than one third 

 of head, nearly equal to interorbital space. Bases of dorsal and anal short, 

 about twice their lengths from the caudal, prominent beyond outline of body. 

 Caudal moderately long, subtruncate, conspicuously wider than caudal pedi- 

 cel, which has a more slender appearance than in other species. Scales 

 medium, regularly placed, thin, flat, not granulate, with very fine striae, those 

 along the vertebral line small, irregular and showing a slight indication of a 

 vertebral keel. Belly appearing naked, but seen under the lens to be nearly 

 covered by smaller scales. Entire space below orbit to preorbital covered 

 with scales. 



Entire body light olivaceous brown to yellowish ; sides below lateral line, 

 belly, cheeks, and throat somewhat silvery. Back above lateral line brown- 

 ish, freckled with faint spots of rusty brown. Dorsal and caudal with irregu- 

 lar transverse series of brownish spots. Young similar in markings, bearing 

 a dark streak in a silvery band along the flank, and more of the silvery tint 

 on cheeks and beneath. Largest specimen at hand three and three fourths 

 inches. 



Lake Titicaca. 



Orestias Agassizii. 



Plate III. Fig. 10, teeth. 



Orestiws Agassii Val., 1816, C. V. Poiss., XVm, 238, pi. 536 ; Blkr., 1860, Cvpr., 487. 

 Orestias Agassizii Gvivm., 1876, Bull. M. C Z., Ill, 275; Eig., 1891, P. u! S. Mus., XIV, 65,— 

 1891, Ann. N. Y. Ac, VII, 629. 



Orestias Tschudii Cast., 1S55, Exp. Am. Sud, Poiss., 51, pi. 27, fig. 1 ; Blkr., 1860, Cypr., 487. 

 Orestias Oweiiii (part) Gtlir., 1866, Cat., VII, 330. 



Orestias Ortonii Cope, 1875, J. Pliil. Ac, 186 ; Eig., 1893, P. U. S. Mus., XVI, 54. 

 Orestias frontosus Cope, 1875, 1. c, 187 ; Eig., 1893, 1. c, 54. 



B. 5; D. 14-15; A. 16-17; P. 17-18; LI. 34-36; Ltr. 14-15; Vert. 15 

 or 14 + 18. 



Body rather elongate and compressed, not rising so high above the pec- 

 torals as in 0. Jiissicui, not angular. Head short, less than depth, four and 

 one fourth times in the length without caudal, rounded on all sides, inter- 

 orbital space much arched both longitudinally and transversely. Snout 

 medium, longer than eye, narrow, blunt, rounded ; chin nearly vertical. 

 Mouth narrow, vertical, cleft extending a little below the lower level of 

 the eye. Teeth small, simple, hooked, inner series smaller ; pharyngeal 



