114 TELEOSTEI : — ACANTHOPTERI. — XX. 



mimitp or ol)s<)U'tc; pri'ojHTcli' rritirc or nearly so; prcorbit.al deep, 

 not sheatliin^i the niaxilliiry ; S''^ uiembranes separate, free from 

 isthmus ; pseiulobranehiie small, concealed. B. usually 6 ; lower 

 pharyngeals separate ; scales usually large ; lateral line present. 

 Dorsal continuous, with to 13 spines; anal spines 3 to 8. Ver- 

 tebra' alx)ut 30. Intestines short, with a few cseca. Sexes similar, 

 but the changes in form due to age often considerable. Genera 10; 

 species alnnit 2.'j ; carnivorous fishes especially charac-teristic of the 

 Mississippi Valley, — all but one (Archopliles interruptus of Cal.) 

 coiilincd to the waters of the E. U. S. Some species build nests, 

 and all are voracious and gamy. 



a. Dorsal fin scarcely larper tlian anal; pill rakers very lonp and slender. 

 b. Spinous dursal longer than soft, its spines 12; anal spines about 8. 



Centuarchus, 149. 

 bb. Spinous dorsal shorter than soft, with 6 to 8 spines; anal spines G. 



POMOXIS, 150. 

 aa. Dorsal fin much larger than anal ; gill rakers shorter. 



c. Body comparatively short and deep, the depth usually more than 2 

 the length; dorsal fin not deeply divided. 

 d. Tongue and pterygoids with teeth; mouth large (the maxillary 

 reaching past middle of eye). 

 e. Scales ctenoid; caudal concave behind. 

 y. Opercle emarginate behind; anal spines usually 6; branchios- 



tegals 6 Amblopi.ites, 151. 



ff. Opercle ending in a black convex process or flap : anal .«pines 3. 



Cn.F-.NOBKYTTl'S, 152. 



ee. Scales cycloid.; caudal convex. . . . Acanthahciius, 153. 

 dd. Tongue and pterygoids toothless ; mouth small (the maxillary barely 

 to middle of eye). 



g. Caudal convex; opercle emarginate, without flap. 

 h. Dorsal fin continuous, normally with 9 spines; anal nor- 

 mally with 3 spines E-nneacaxtius, 154. 



hh. Dorsal fin angulatcd, some of the median spines elevated; 

 dorsal spines 10; anal 3. . . . MKsocio.visTics, 155. 

 gg. Caudal margin concave; opercle prolonged behind in a con- 

 vex processor flap which is always black; dorsal spines 



normally 10; anal 3 l.EitiMis, 156. 



OC. Body comparatively elongate, the depth in adult about \ the length; 

 D. low, deeply emarginate, with 10 spines; mouth large; ('. lunate. 



MiriioiTEKis, 157. 



149. CENTRARCHUS Cuv. & Val. {Kivrpov, spine ; 

 aji\o<:, iinus.) 

 207. C. macropterus La( epcde. H(Mly ovate ; fins high. Green, 

 •with rows of dark brown spots along siiK-s ; fins reticulated; yctung 

 •with a bl.ick ocrlliis on I), behind. IK-ad 3^ ; depth 2. Scides 

 6_44_14. I). XI or XII. 12. A. VII or VI II. l.'i. L. (i. N. C. 

 to 111., and S., in lowland .strc;ims. {^ulK^>ui, long; rrrt/joe, fin.) 



