SCIENTIFIC HISTORY OF THE BLACK BASS. 21 



Scales of interoperculum uniserial 



Covering only about half the Covering the entire width of 

 width of the bone. the bone. 



Scales of preopercular limb 



None. Developed in an imperfect row 



(e. g., 3-5 in number). 



Scales on dorsal 



Developed as a deep sheath (in- Developed as a low (obsolete) 

 volving last spine) of small scales shallow sheath, and with series 

 differentiated from those on the ascending comparatively little 

 back, and with series advancing on membrane behind the rays 

 high up the membrane behind (none behind the last five or 

 each ray (except last two or six), 

 three). 



Scales on anal 



Ascending high behind each None (or very few), 

 ray. 



Mouth 

 Moderate. Large. 



Supramaxillary 



Ending considerably in front of Extending considerably behind 

 hinder margin of orbit (about the posterior margin of orbit, 

 under hinder border of pupil). 



Rays 



Dorsal, articulated, 13. Dorsal, articulated, 12 (I. 11). 



Anal III, 10-11. Anal III, 10. 



Pectoral, 1 -16-1-17. Pectoral, 1-14 (1-13). 



Dorsal fin in front of soft portion 



Little depressed, the ninth spine Much depressed, the ninth spine 



being only about a half shorter being only about a fourth as long 



than the longest (3, 4, 5) and a as the longest and half as long 



fourth shorter than the tenth. as the tenth. 



