360 FISHES OF WESTERN SOUTH AMERICA 
just exceeding the eye; eye large, 4.0 in the head, which is everywhere narrow with 
no protrusion of the opercle, and little modification of the juvenile scales; about 25 
in the vertebral series, a naked area on each side, elsewhere very irregular, the 
number small; pectoral well surrounded by scales, short, not reaching half way to 
anal base; opercle silvery; peduncle depth 1.25 times eye. 
477. ORESTIAS PENTLANDII Valenciennes 
Plate XVII, figs. 3 and 4 
Orestias pentlandit Valenciennes, 1839, L’Inst., VII, 118; 
Cuvier and Valenciennes, 1846, Hist. Nat. Poiss., XVIII, 172, pl. 533; 
Castelnau, 1855, Anim. Amér. Sud, Poiss., 52; 
Figenmann and Eigenmann, 1891, Proc. U.S. Nat. Mus., XIV, 65; 
Garman, 1895, Mem. Mus. Comp. Zool., XIX, 148; 
Steindachner, 1902, Denksch. Xk. Akad. Wiss. Wien, LX XII, 58, pl. iv, fig. 4; 
Pellegrin, 1904, Bull. Soc. Zool. France, XXIX, 92; 
Starks, 1906, Proc. U. S. Nat. Mus., XXX, 779; 
Pellegrin, 1906, Poiss. Lacs. Hauts Plat. Amér. Sud, 126, 127, 129, fig. 191; 
Eigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, III, 461; 
Evermann and Radcliffe, 1917, Bull. U.S. Nat. Mus., no. 95, 39. 
Orestias bairdit Cope, 1875, Jour. Acad. Nat. Sei. Phila., 1871-1874, 185. 
Lake Titicaca 
16082, 4, 180-190 mm., Capachica, Lake Titicaca, Allen, November, 1918. 
16083, Yunguyo bay, Lake Titicaca, Allen, November, 1918. 
16084, Pomata bay, Lake Titicaca, Allen, December, 1918. 
16085, 3, 161-175 mm., Lake Arapa, Allen, January, 1919. 
Elongated, little elevated; width in depth 1.3; depth in length of the head 1.3; 
head long, 3.7—-4.0 in length without caudal; trunk rounded, becoming compressed 
toward caudal peduncle; dorsal and ventral contours uniformly and moderately 
convex. 
Crown slightly convex, broad, flat, scaled or naked; eye in the interorbital space 
2.4; snout moderately long, containing eye 1.4 times, narrowing to a moderately 
broad, rounded, blunt muzzle; mouth small to medium, 1.2 times eye, gape moder- 
ate, Just reaching, or not reaching, lowest level of the orbit, oblique; head long, con- 
taining eye 5.4-6.0 times, opercle especially long; teeth rather few, the second 
series weak, deciduous. 
D. 11-18, short, erect, the longest rays equal to the length of the base; A, 
13-15, its elevation greater than the length of the base; P. 18-19, broad, triangular, 
the last rays diminishing, the longest ones more or less half way to the anal origin; 
C. large, broad, slightly emarginate. 
Scales of the crown rather deciduous, with a scaleless area sometimes on either 
side of the back; granulations of scales not extreme, rather smooth; infraorbital, 
lower opercle, prepectoral, and a wide area on the venter, including anal basis, 
without scales. A pentagonal or subrhomboidal bony plate occupies the preorbital 
space to the maxillary; a similar pair of narial plates, roundly triangular, overroof 
the snout; the first nares much reduced, pore-like. Body scales tend to be much 
less regular than in most species. 
