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 striae. 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 

 cases preceded by yellowish. Across the bases of the caudal rays there is a 

 nan'ow 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 j^ortion. 



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. 



Cyprimdon elegans B. & G., 1854, P. Phil. Ac, 1S53, p. 389 ; Grd., 1859, Mes. Bd. Sur., Fisli, 66, pi. 

 37, fig. 1-7 ; Blk., 1860, Cypr., 48i ; Trosch., 1865, Verz. Wirb. Mex., 104 ; Jor. & C, 1877, B. Buf. Soc, 

 III, 141; Jor., 1878, B. U. S. G. Sur., IV, 432,-1887, B. U. S. P. 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. P. Com., 1892, 

 pp. 66, 75, 83, 87, 92, 106 ; Woolm., 1894, B. U. S. P. Com., 59. 



Vyprinodoti eximius Grd., 1859, P. Phil. Ac, 158 ; Blk., 1860, Cypr. 484; Jor. & G., 1882, B. 16 U. S. 

 Mas., 890; Jor., 1887, R. U. S. F. Com., 835; Woolm., 1894, B. U. S. P. Com., 59. 



B. 6; D. 12-11; A. 11-10; V. 6-7; P. 15-16; LI. 27-30; Ltr. 12. 



Outlines similar to those of C. gibbosiis, 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 ; 

 chin steep. Eye shorter than snout, two sevenths of head, three fourths of 



