466 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY - IV. 



usually with 7 spines. Caudal emarginate. Scales strongly ctenoid. 

 California. (/>/"?, anus; Z-krr^, armed.) 



726. A. iiitcrrniptiis (Grd.) Gill. Sacramento Perch. 



Body oblong-ovate, compressed, the back considerably elevated ante- 

 riorly, depressed over the eye, the snout projecting at an angle. Mouth 

 terminal, very large, the maxillary very broad, extending beyond pupil. 

 KYM very large, 4 to 5 in head. Scales on cheek in about eight series. 

 Dorsal spines rather low, strong; anal spines similar. Pectoral short, 

 barely reaching anal. Color blackish above, sides silvery, with about 

 seven vertical blackish bars, irregular in form and position and more or 

 less interrupted; a black opercular spot; fins nearly plain. Head2; 

 depth 2. D. XEII, 10; A. VII, 10; scales about 7-51-14. L. 12 inches. 

 Sacramento and Sau Joaquin rivers; abundant; the only fresh-water 

 percoid west of the Eocky Mountains. 



(Centrarchits iiitcrruptus Girarcl, Proc. Acad. Nat. Sci. Phila. 1854, 129: Anibloplitea 

 itiiirrnptns Girard, U. S. Pac. R. R. Surv. Fish. 10: Centrarchits intcrrnjitus GUuther, 

 i, 237 : Ccntrarchuu maculosus Ayres, Proc. Cal. Acad. Nat. Sei. i, Id54, 8.) 



245. AMBILOPLITES Rafiuesque. 

 Rock Bass. 



(Rafinesque, Ichth. Oh. 1820, 33: typeXepomis icthcloidcs Tia.=Bodicmusrup6stri8 Raf.) 

 Body oblong, moderately elevated, compressed. Mouth large, the 

 broad maxillary with a well-developed supplemental bone ; lower jaw 

 projecting. Teeth on vomer, palatines, tongue, and pterygoids ; lingual 

 teeth in a single patch ; pharyngeal teeth sharp. Branchiostegals G. 

 Opercle ending in 2 flat points; preopercle serrate at its angle; other 

 membrane bones chiefly entire. Gill-rakers rather long and strong, 

 dentate, less than 10 in number, developed only on the lower portion 

 of the arch. Scales large, somewhat ctenoid. Dorsal fin much more 

 developed than the anal fin, with 10 to 11 rather low spines; anal spines 

 normally (. Caudal fin emarginate. (w/^SAyc, blunt; J-xirr,-, armed.) 



727. A. rcspestris (Raf.) Gill. Common Rock Bass; /,'*,//> : t;<i<itil<--Eye. 



Body oblong, moderately compressed. Head large, the profile little 

 depressed above the eye. Month large, the maxillary extending to 

 opposite posterior part of pupil. Eye very large, 3i in head. Gill 

 rakers feu, about 10 developed. Scales on cheeks in <> to8 scries; pre- 

 opercle serrate near its angle. Color olive green, brassy-tinged, with 

 much dark mottling; the Young irregularly barred and blotched with 

 black, the adult 'with a dark sp:>t on each scale, these forming inter- 



