THE CYPRINODONTS. 99 



B. 5 (rarely 6); D. 11-13; A. 10-12; V. 6 ; P. 17-19; Vert. 14-15 + 



19-20. 



Moderately stout, compressed posteriorly, depressed on the head ; arch 

 from head to dorsal rather low ; depth in front of dorsal equal length of 

 head, or one half more than depth of caudal pedicel. Head two sevenths of 

 the length to the base of the caudal, as broad as deep, flattened on the crown. 

 Snout as long as eye, blunt, rounded ; chin convex, moderately steep. Mouth 

 nearly twice as wide as eye. Teeth conical, in bands, outer series larger ; 

 pharyngeal with a shoulder, some of the median larger, compressed, swollen. 

 Eye medium, once in snout, twice in interorbital space, four and a half times 

 in the head. Cheek scales in three rows below the orbit. Dorsal and anal 

 little behind the middle of the total length ; dorsal origin midway from head 

 to base of caudal ; fin not reaching as far backward as the anal. Base of 

 anal opposed to that of dorsal, hardly reaching as far either forward or back- 

 ward as that of dorsal. Fins comparatively large and broad, varying with 

 age and sex. Caudal deep, subtruncate to I'ounded. Pectorals wide, short, 

 rounded, reaching a vertical from the bases of the ventrals. Scales large, 

 striate. Oviduct adherent for some distance along the first ray of the anal. 

 Intestine as long as the fish. A few individuals have six branchiostegal rays 

 instead of five. 



Males are most often olivaceous, darker on the back, lighter to white or 

 silvery beneath, with a dozen or more narrow vertical bars of light color 

 across the flanks, and with a black spot edged with white on the hind rays 

 of the dorsal. Fins and body are more or less marked with small spots, 

 bars, or dots of dark and of light colors. A black spot sometimes present on 

 the hind rays of the anal ; and not rarely the hind margins of dorsal, anal, 

 and caudal are whitish. On some individuals of this sex the colors are more 

 like those of the females. Southward the silvery spots and dots are more 

 distinct on body and fins. As in the salmon and trout the silver color is 

 more prevalent in salt-water specimens, and no doubt fresh-water examples 

 change on entering the sea. 



Females are not so brightly colored as males ; some are nearly uniform 

 brownish on the backs, lighter below, with a darker spot on each scale ; others 

 have vertical bars or spots of brownish on the flanks. The vertical silvery 

 streaks are frequently met with, but less distinct. In cases a silvery tint 

 extends the length of the body on the middle of the side. The spot on 

 the dorsal is rarely present on the female. Generally the lower half of the 



