THE CYPRINODONTS. 153 



anal little nearer the latter ; pectorals broad, rounded, reaching more than 

 half way to the anal ; caudal pedicel deep, the fin deepei- than long, 

 subtruncate. 



Color of specimens of four and a half inches, olive, darker on back, sil- 

 very on belly and throat ; fins paler, uniform, or with a darker streak around 

 the base of the caudal. Three inch specimens are olive, with faint mot- 

 tlings- of darker, on head, body, and fins, silvery on flanks and lower surfaces, 

 and dark on the chin. Individuals of two inches are olivaceous mottled with 

 brownish, with silvery cheeks and a silvery band along the lateral line ; belly 

 whitish. 



Compared with 0. Mem, in specimens of equal length, this species is 

 much less rough and angular, and has a different coloration, a smaller mouth 

 and less arch to the back. Lake Umayo, whence the specimens were brought, 

 is said to be without an outlet, nine miles northwest of Lake Titicaca, and 

 four hundred feet higher. 



Orestias albns. 



Oreslias albus Val., 1839, L'Inst., VII, 118, — 1846, C. V. Poiss., XVni, 242, pi. 537 ; Bikr., 1860, 

 Cypr., 487; Garm., 1876, Bull. M. C. Z., Ill, 276. 

 Orestias Mullen (part) Gthr., 1866, Cat., VI, 330. 



B. 5; D. 14-15; A. 14-16; P. 21; LI. 31; Ltr. 12 ; Vert. 13 + 18. 



Body short, stout, compressed, rising high above bases of pectorals, great- 

 est depth about equal to length of head. Head large, about two fifths of 

 the length of the body without the caudal, lateral angles blunt, crown flat 

 to concave. Snout large, longer than eye, wide and deep, greatest width 

 about half that of head, chin prominent. Mouth large, vertical, cleft de- 

 scending little below the level of the lower edge of the eye. Teeth not 

 as numerous or sti'ong as those of 0. Cuvieri. Eye medium, two elevenths of 

 the head, equal to distance from the mouth, two thirds of snout, more than 

 half of the interorbital space. Scales large, rough with granulations, largest 

 on head and above pectorals, fourteen to fifteen wide ones between head and 

 dorsal, three rows below the eye, lacking behind the preorbital and at each 

 side of the vertebral series. Base of dorsal its length from the caudal, origin 

 half way from the latter to the head. Margins of pectorals, dorsal and anal 

 rounded. Caudal subtruncate with angles rounded, half as long as head. 



Brown to olive, dark to light yellowish or whitish, centres of scales 

 lighter; white to yellowish below. Specimens described five and a half 



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