232 Field Columbian Museum — Zoology, Vol. V. 



Color nearly uniform light olive, with minute darker punctulations, 

 which sometimes form darker margins to the scales ; an oblique dusky 

 streak on opercle ; 3 or 4 oblique obscure dark cross-bars on spinous 

 dorsal and 4 or 5 on caudal peduncle; ventral with white pigment. 

 Length about 2 inches. 



88. Chonophorus Poey. 



Chonophorus Poey, Memorias, 11, 274, 1861. (Type, Gobius taiasica 

 Lichtenstein.) 



Body elongate, compressed posteriorly; head large, preorbital 

 region very long; mouth large, nearly horizontal; inner edge of 

 shoulder girdle with 2 or more conspicuous dermal flaps; premaxillary 

 and maxillary strong; lips thick; scales small, ctenoid; interorbital 

 groove with a conspicuous median crest; ventrals united, not adnate 

 to the belly. 



A group of fishes which inhabit the fresh waters of Tropical Amer- 

 ica and the Hawaiian Islands. Some of the species reach a large size. 

 I recognize with some doubt three species of this genus in Mexico. 



KEY TO THE SPECIES OF CHONOPHORUS. 



a. Scales large, 60 to 75 in the lateral series. page 

 b. About 15 scales in a series between second 



dorsal and base of anal nelsoni, 232 



bb. About 21 scales in a series between second 



dorsal and base of anal taiasica 233 



aa. Scales smaller, 24-76 to So mexicauus 233 



221. Chonophorus nelsoni (Evermann). 



Awaous nelsoni Evermann, Proc. Biol. Soc. Wash., 1898, 3; fresh 

 water pools at Rosaria, Sinaloa: Jordan & Evermann, Bull. 47, 

 U. S. Nat. Mus., 1896, 2235. 



Streams of Sinaloa. 



Head 3^; depth 6; D, vi-ii; A. 11; scales about 63. Body 

 oblong, compressed; head large, flat above; maxillary reaching ver- 

 tical from posterior margin of pupil; teeth on bands in jaws, some of 

 the outer a little enlarged; eyes moderate, $% in head; scales small, 

 ctenoid, crowded on anterior part of the body; about 15 scales in a 

 series between soft dorsal and anal fin ; caudal fin rounded. 



Color grayish ; head mottled and blotched with dark ; side with 7 

 or 8 black blotches, the largest under the middle of the pectoral fin; 

 dorsals pale, crossed by several lines of black spots; caudal pale, with 



