216 ON THE DISTRIBUTION OF FRESH-WATER FISHES 



CENTRARCHID^. 



For convenience of reference, and illustration of the present essay, the following 

 comparative table of genera allied to the Pomotis is given : 



I. Dorsal fin longer than anal. 



a. Operculum with two posterior points. 



/9. Dorsal fins deeply divided, approaching separation. 

 Palatine teeth ; spinous dorsal radii x ; caudal emarginate, . . Micropterus. 



j3^. Dorsals continuous. 

 Palatine teeth ; dorsal spines x ; scales ctenoid, caudal emargin- 

 ate. A. V, vi, . . Ambloplites. 



Palatine teeth; dorsal spines. x; scales cycloid; caudal convex. 



A. V, vi, ACANTHARCHUS. 



Palatine teeth ; D. ix. A. iii ; caudal convex, ..... Ekneacanthus. 

 Palatine teeth ; D. viii. A. iv ; caudal convex, .... Hemioplites. 



Palatine teeth ; D. x. A. iii ; caudal convex, .... Mesogonistixjs. 



aa. Operculum with an entire convex process; D. x. A. iii. 

 Palatine teeth ; present or absent; inferior pharyngeals conic ; caudal 



emarginate, Lepomi§. 



No palatines ; inferior pharyngeals paved ; caudal emarginate, . Pomotis. 



II. Dorsal fin of equal basis and extent with the anal- Pala- 



tine teeth. 

 Spinous dorsal longer than cartilaginous, forming an angle with it, Centrarchus. 

 Spinous dorsal shorter than articulated, continuous with it. D. vii — 



viii, Hyperistitjs. 



Dorsal as in last, except with vi rays, ...... Pomoxys. 



MICROPTERUS Lac. Gill. 

 Grystes Cuv., Dioi)lites Rafinesque. 



Micropterus fasciatus Gill. 

 Proc, A. N. Sci. 1865, 83. Oiclila Leseur, Orystes Agass. 



This species is abundant in the Holston River; individuals are identical with others 

 from the Miami R., Indiana, the Wabash, the Kiskiminitas, from Michigan and Lake 

 George, N. Y. It grows to a considerable size and is much valued as food. 



The Academy possesses specimens of M. nigi-icans or a nearly allied species from 

 the lower part of James River, Va. 



The absence or rarity of this species and the Amhloplites rupestris in the Kanawha 

 River, in Giles county, and above is remarkable. During a residence of over six 

 weeks on its banks I never caught or saw a specimen of either, and they were not 

 clearly known to the fishermen. 



