1124 Bulletin 4j, United States National Museum. 



more than half leugtli of suout; preorbital with strong retrorse serr^. 

 Top of head narrower than in C. armattis and more strongly ridged; 

 the two interior ridges on the interorbital space separated by a space 

 little wider than the nostril, coalescing opposite the nostrils and forming 

 a single ridge for a little distance forward to near the base of the spines 

 of the premaxillary. Preopercle with rather distant teeth of nearly 

 equal size on the entire length of its vertical margin; similar teeth on 

 the horizontal part, growing larger backward; about 2 teeth at the 

 angle much longer and stronger than the others ; suprascapula with 5 

 or 6 strong teeth ; subopercular flap reaching about to front of spinous 

 dorsal. Gill rakers long, about j diameter of orbit. Dorsal spines high 

 and rather strong, but distinctly slenderer and more flexible than in 

 C. armatua, their tips when depressed reaching considerably farther back 

 than the tips of the pectorals or ventrals; third spine longest, a little 

 less than half length of head ; fourth spine but little shorter than third ; 

 insertion of first dorsal spine a trifle nearer last ray of second dorsal 

 than tip of snout ; second anal spine very long and strong and straight or 

 more or less curved, its length and form very variable, its tip about 

 reaching base of caudal ; much longer than third dorsal spine or than 

 third anal spine, and about 1^ in length of head ; third anal spine about 

 equal to first soft ray ; caudal fin well forked ; ventral fins long, reaching 

 in most cases scarcely to the vent ; pectorals about equaling ventrals, Ij 

 in length of head, not reaching tips of ventrals. Vent about midway 

 between base of ventrals and middle of base of anal. Color bluish, 

 olivaceous, silvery white below ; lateral line pale ; membrane of anterior 

 dorsal spines and of second and third anal spines blackish; pectorals and 

 soft parts of vertical fins somewhat dusky ; ventral plain bright yellow; 

 anal with more or less of bright yellow. Length about 1 foot. Pacific 

 coast of Mexico from Mazatlan to Panama; generally common, espec- 

 ially about Mazatlan, where it enters the streams in abundance. Proba- 

 bly not distinct from C. ensiferus. (Rohalito, the vernacular name; 

 diminutive of Rohalo.) 



Cenlropomus robalUo, Jordan & Gilbert, Proc. U. S. Nat. Mus., 1881, 462, Mazatlan ; Aca- 

 pulco. (Types, Nos. 28102, 28132, 28150, etc. Coll. Gilbert.) 



1527. CENTROPOMUS AFFINIS, Steindacbner. 



Head 21; depth 3i ; eye large, 4 in head. D. VIII-I, 10; A. Ill, 6; 

 scales 7-46-11 (Vaillant), 7-47 to 50-10 or 11 (Steindacbner). Snout 

 depressed, its profile a little concave; back not much elevated; sides 

 compressed, parallel ; line of belly straight. Maxillary reaching to first 

 third of eye ; suborbital with 5 or 6 small teeth ; preopercle with 2 large 

 triangular teeth at angle, the other teeth strong; subopercular flap 

 reaching base of first dorsal spine. Scales large, those before dorsal 

 small. Suprascapula with 4 teeth. Ventral reaching more than half 

 way to anal; i^ectoral If in head; third dorsal spine 11 in depth of body, 

 about 2i in head; second anal spine notably longer than third, its length 

 If in head, i^q- greater than depth of body ; caudal a little shorter than 



