Jordati and Evertnan/i. — Fishes of North A?nerica. 985 



pterygoids, and hyoid. Premaxillaries protractile ; maxillary with a sup- 

 plemental bone in the large-monthed forms, sometimes minute or obsolete 

 in others. Preopercle entire or somewhat serrate ; opercle ending in two 

 flat points or prolonged in a black flap at the angle. Preorbital short and 

 deep; first suborbital narrow, the maxillary not slipping under its edge. 

 Nostrils 2, on each side. Gills 4, a slit behind the fourth. Pseudo- 

 branchice small, almost glandular, nearly or quite covered by skin. Gill 

 membranes separate, free from the isthmus. liranchiostegals 6, rarely 7. 

 Gill rakers variously formed, armed with small teeth ; lower pharyngeal 

 bones sejiarate, their teeth conic or sometimes paved. Cheeks and opercles 

 scaly ; body fully scaled, the scales usually not strongly ctenoid, rarely 

 cycloid; lateral line present, usually complete. Dorsal fins confluent, 

 the spines 6 to 13 in number (usually 10), depressible in a shallow groove ; 

 anal spines 3 to 9. Intestinal canal short. Pyloric coeca 5 to 10. Verte- 

 brae 28 to 35 (13 to 18 -f 15 to 17), Entopterygoid present. Precaudal or 

 abdominal vertebra? with transverse processes from the third or fourth to 

 the last ; ribs all but the last 2 to 4 sessile, inserted on the centrum behind 

 the transverse proceses. Frontals with a pair of large muciferous chan- 

 nels which converge posteriorly or are confluent with a transverse channel 

 connecting the jiostfrontals, their posterior openings close together on the 

 median line in front of the supraoccipital crest. Coloration usually bril- 

 liant, chiefly greenish. Sexes similar ; changes with age often great. 

 Fresh-water fishes of North America ; genera 12 ; species about 30, form- 

 ing one of the most characteristic features of our fish fauna. Most of 

 the species build nests, which they defend with much courage. All are 

 carnivorous, voracious, and gamy. All are valued as food, their impor- 

 tance being in direct proportion to the size which they attain. The 

 group has been divided by Dr. Gill into three subfamilies very closely 

 related to each other — CentrarcMnxp, Lepomime, and MicropUrlna'. Most of 

 the species belong to the Lepominw. The Microptcrinw approach most 

 nearly to the Serranidcv,. At the same time they are perhaps farthest from 

 the primitive stock from which the group has sprung. {Pcrcidiv, group 

 GrysUna, Giinther, Cat., i, 256-261, 1859.) 



Centrauchin.t: : 

 a. Dorsal fin scarcely longer than anal. 



6. Dorsal spines 5 to 8; anal spines G; spinous dorsal shorter tlian soft dorsal; bpdy elo igate, 

 rompressad. PoMoxis, 450. 



hb. Dorsal spines 11 or 12; anal spines 7 or S; spinous ilorsal longer than soft dorsal; body 

 short and deep, compressed. Centuauciics, 4,'jl. 



(I'l. Dorsal fin much larger than the anal; gill rakers rather short. 

 LKPOMiN/r. : 

 ('. Body comparatively short and deep, the depth tisuiilly more than J the length; dorsal 

 fin not deeply eniarginate. 

 tl. Tongue and pterygoids with toetli; mouth large, maxillary reaching past middle 

 of eye. 

 e. Scales cycloid; caudal convex. Acantiiarmu's, 452. 



ee. Scales ctenoid; caudal concave behind. 



/. Opercle emarginate behind; anal spines 5 to 8. 



g. Lingual teeth in a single jiatch; gill r.akers about 10; preopercle ser- 

 rate only at its angle, other membrane bones entire; lower point 

 of opercle without pointed stria'. Amdloplitbs, 453. 



