FISHES OF SINALOA. 421 



Head 4^; depth 4^ to 5; dorsal IV-I, 8; anal I, 

 21; scales 40-11; pectoral ^ longer than head, 4^ in 

 body; anal base more than half longer than head, 3 in 

 body; eye 2^ in head; snout 35^; maxillary 2^; 

 lower jaw 23^. 



Body rather deep and compressed; snout shortish; 

 opercle shortish, rounded behind; mouth small, the upper 

 jaw very protractile, the premaxillary strongly curved; 

 jaws equal; teeth rather strong, the outer curved, those 

 in upper jaw largest; eyes very large, silvery; breast 

 compressed, as in Thyrina evermanni, but less sharp at 

 edge, appearing as if pinched between thumb and finger; 

 pectoral long, pointed, not truly falcate, reaching more or 

 less past the middle of the short ventrals, its posterior 

 margin not concave, the middle rays considerably more 

 than half length of upper rays; dorsal and anal naked; 

 gill-rakers numerous, long and slender; first dorsal small,, 

 behind front of the long anal, midway between gill open- 

 ing and base of caudal; first ray of soft dorsal over about 

 fourth of anal; last rays of soft dorsal considerably be- 

 fore last of anal. Caudal lunate, the lower lobe the 

 longer and broader, as long as head. Color, translucent 

 green, with considerable dusky dottings, no yellow; fins 

 dotted; ventrals black, as are lobes of second dorsal and 

 anal; silvery stripe narrow, little more than half diameter 

 of the eye; first dorsal and base of anal dusky; air- 

 bladder evident through the translucent sides of body,, 

 but less clearly so than in Thyrina evermanni. 



In fresh water, very common in the lower Presidio; 

 many specimens taken; the longest 3^ inches long. 

 Type, No. 2685, L. S. Jr. Univ. Mus. 



