FAMILY PERCIDJS. 27 



GENUS CENTRARCHUS. Cuvier. 



Preopercle not denticulated. Velvet-like teeth in the jaws, front of the vomer, on the pala- 

 tines, and base of the tongue. Angle of the opercle divided into two flat points. Anal 

 spines usually numerous. Body oval, compressed. A single dorsal. 



Obs. This is a numerous group in the United States. 



FRESH-WATER BASS. 



Centrarchos .enecs. 



PLATE II. FIG. 4. — (STATE COLLECTION.) 



Ctchla anea. Lesueur, Journ. Acad. Nat. Sc. Vol. 2, p. 214, pi. 12. 

 Cenlrarcus <mtcus. Cuv. et Val. Hist, des Poiss. Vol. 3, p. 84. 

 Cichla mnea, Rock Bass. Kirtland, Zool. Ohio, p. 16S and 190. 



Characteristics. Dark greenish bronze, with 5-6 series of irregular subquadrate spots on the 

 sides below the lateral line. Anal fin with six spinous rays. Length 

 6-10 inches. 



Description. Body short, compressed ; its height rather exceeding the length of the head 

 measured to the posterior angle of the opercle. Head scaleless between and anterior to the eyes. 

 Scales small on the preopercle, larger on the opercle ; slight indications of serratures about 

 the angle of the preopercle. Scales adherent ; on the sides, large and rounded, and, under 

 the lens, denticulated on their free margins, truncated and plicated at their bases. Thirteen 

 rows of scales below the lateral line, and about six above ; they ascend upon the bases of the 

 dorsal, anal and caudal fins, forming a sort of sheath as in the family Scienid;e. Lateral line 

 concurrent with the back, and composed of a series of single tubes ; in some individuals, I 

 have noticed this line to be distorted in a very anomalous manneT. Eyes very large, and 

 rather prominent. Nostrils small and double. Opercle with the rudiments of a double angle 

 on the posterior margin. Lower jaw somewhat longest. Teeth small, subequal, conical, 

 recurved ; on the jaws, vomer, palatines and pharyngeals. Stomach with from five to seven 

 short cascal appendages, and filled with the young of a species of Astacus or crayfish. 



Dorsal fin long, commencing above the ventrals, and composed of eleven spinous and twelve 

 articulated rays : the first, second and third rays of the spinous portion successively longer ; 

 the remainder subequal, and all acutely spinous : the articulated portion rounded, with longer 

 rays ; the sixth, seventh and eighth exceeding the others in height. The pectorals broad and 

 rounded, composed of fourteen rays. Ventral fins placed just behind the pectorals, and com- 

 posed of one weak spine and five multifid rays, the last connected to the body by a broad trans- 

 parent membrane. Anal fin compound ; arising under the eighth spinous ray of the dorsal fin, 

 and comprising six spinous and eleven articulated rays ; the first spinous ray very short, the 



