116 TELEOSTEI: ACAXTHOPTERI. — XX. 



154. ENNE ACANTHUS Gill. (t'jWn, nine; uKavda, spine.) 



a. Depth usually more than half length; opercular spot large, more than 

 half eye. 



303. E. obeaus (Baird). Olivaceous, with 5 to 8 distinct dark 

 cross-bars; spots on body and fins golden or purplish; cheek with 

 lines and spots ; a dark bar below eye ; cheek with 4 rows of scales ; 

 lateral line usually incomplete; fins moderate, spine of V. not 

 reaching vent. Head 2f; depth If. D. IX, 10. A. Ill, 10. 

 Stales 4-32-10. L. 4. Mass. to Fla., common coastwise. (Lat., 

 fat.) 



aa. Depth usually less than half length ; opercular flap small, bordered with 



pearly and blue. 



304. E. simulans (Cope). Dark olive, young faintly barred; a 

 dark bar below eye ; £ with head, body and vertical fins with 

 round sky-blue spots ; 9 duller, with lower fins and larger, faint 

 spots ; lateral line usually complete. Head 2| ; depth 2^. D. IX, 

 10. A. Ill, 9. Scales 3-30-9. L. 5. X. J. to S. C, com- 

 mon coastwise; (number of spines sometimes variable). (Lat., 

 resembling.) 



305. E. eriarchus (Jordan). Olivaceous ; vertical fins with 

 round pale spots; lateral line incomplete; fins very large, espe- 

 cially A., which is reached by the ventral spines ; scales on cheek, 

 in 3 rows. Head 2f ; depth 2\. D. X, 9. A. IV. 8 (in typical 

 example probably abnormal). Scales 4-33-10. L. 3. Wis. to 

 Mo. ; two specimens known, (ept, an intensive particle ; apxes, 

 anus.) 



155. MESOGONISTIUS Gill, (fxlaos, middle; ycovia, angle; 



[(tt'iov, sail.) 



306. M. chaetodon (Baird). Body suborbicular, the mouth 

 very small, the fins high. Straw-color, with dark clouds ; 6 to 8 

 irregular, sharply-defined black bars across body and fins, the first 

 bar through eye. Head 3; depth If. D. X, 10. A. 111,12. 

 Scales 4-28-10. L. 3. X. J. to Md., in sluggish streams; hand- 

 somest of the Sun-fishes. (A genus of fishes.) 



156. LEPOMIS Rafinesque. Sun-Fishes. (Ichthelis, Pomotis, 



and Apomotis Rafinesque.) 

 (A large genus, one of the most difficult in our fauna, as the 

 species are subject to great individual variations, especially with 

 age. On the other hand the numbers of scales and fin-rays are 

 essentially alike in all, and nearly all the distinctive characters are 

 subject to intergradation. The spines are generally higher in the 

 young, while the "ear-flap" is fully developed only in the adult.) 

 (Xenis, scale ; 7ra>/xa, opercle.) 



