~s 
THE CYPRINODONTS. 23 
little farther back than in dorsal; origin below hinder half of dorsal base. 
Ventrals small, more often with six rays, sometimes with five. Pectorals 
moderate, reaching behind a line uniting bases of ventrals and origin of dorsal. 
Scales large, harsh with striw. On some individuals the edges of the scales 
about the head are beset with short spines. Similar spines are seen along 
the anterior rays of the anal fin. Caudal deeper than long, two thirds as 
long as head, truncate. Intestine long, more than twice the total length of 
the specimen. 
Viewed from above the appearance is black. On the flank there is a 
brown band from the eye to the middle of the base of the tail; above this 
there is a narrower more or less indistinct band of silvery ; below it there 
is a wider band of yellowish, and below the latter from the pectorals to the 
lower edge of the caudal there is a fainter band of brownish. Cheeks brown. 
Lower surfaces silvery to yellowish. Dorsal brown; pectorals, anal, and ven- 
trals brownish. On lighter colored fins there is a narrow margin of black, in 
eases preceded by yellowish. Across the bases of the caudal rays there is a 
narrow vertical bar of brown. Between this bar and a broad margin of 
black the fin is yellowish to brownish yellow, more intense at the edge of 
the black border. The black tip of the fin is much broader than in the 
other species, varying from one third to one half of the free portion. 
The variations in shape from small to large individuals are the same as 
in C. variegatus. In colors the variation is greater, being much lighter and 
more silvery in the young; the pattern in the numerous specimens examined 
varies but little, which may be accounted for by the fact that all were secured 
at one locality. 
Parras, Mexico. 
Cyprinodon elegans. 
Cyprinodon elegans B. & G., 1854, P. Phil. Ac., 1853, p. 389; Grd., 1859, Mex. Bd. Sur., Fish, 66, pl. 
37, fig. 1-7; Blk., 1860, Cypr., 484; Trosch., 1865, Vers. Wirb. Mex., 104; Jor. & C., 1877, B. Buf. Soc., 
III, 141; Jor., 1878, B. U. S. G. Sur., IV, 432, —1887, R. U. S. F. Com., 835; Jor. & G., 1882, B. 16 
U. S. Mus., 329; G. & B., 1883, P. U. S. Mus., V, 239; Everm. & K., 1894, B. U. S. F. Com. 1892, 
pp- 66, 75, 83, 87, 92, 106; Woolm., 1894, B, U. 8. F. Com., 59. 
Cyprinodon eximina Gri., 1859, P. Phil. Ac., 158; Blk., 1860, Cypr. 484; Jor. & G., 1882, B. 16 U.S. 
Mus., 890; Jor., 1587, R. U. S. F. Com., 835; Woolm., 1894, B. U. S. F. Com., 59. 
B.6; D. 12-11; A. 11-10; V. 6-7; P. 15-16; Ll 27-830; Ltr. 12. 
Outlines similar to those of C. gibosus, possibly a trifle more elongate. 
Body compressed, depth two fifths and head one third of the length from 
snout to caudal base. Crown arched. Snout short, blunt, longer than eye ; 
ehin steep. Eye shorter than snout, two sevenths of head, three fourths of 
