216 APPENDIX F. FISHES. 



FISHES. 



BY S. F. BAIRD AND C. GIRARD. 



1. POMQTIS LONGULUS, B. & G = 

 Zoology, PI. XII. 



Spec. char. — General form elongated. Opercular flap rather small 

 and entirely black. Twenty seven to twenty-nine rows of scales across 

 the line of greatest depth of body, and about thirteen rows on the tail. 

 Fifty-two scales in the lateral line. 



Syn. — Pomotis longulus, B. & G. Proc. Acad. Nat. Sc. Philad. VI, 

 1853, 391. 



Description. — The body is very much compressed, and more elon- 

 gated than usual in the genus Pomotis — so much so, indeed, as to re- 

 semble Grystes even more than Centrarchus. The head constitutes a little 

 less than the third of the total length, including the caudal fin ; it is 

 subcorneal, with a little depression upon the middle of the skull. The 

 eyes are large and circular, and their diameter is contained five times 

 in the length of the head, measured from the tip of the snout to the 

 extremity. of the opercular flap. The posterior extremity of the maxillary 

 reaches a point opposite the middle of the pupil. The cheeks are densely 

 covered with small and imbricated scales. The largest scales are on the 

 opercular apparatus, (the preopercular excepted,) where they are also 

 imbricated. The opercular is subtriangular ; its upper angles rounded, 

 and the posterior one terminated by a membranous and rather small flap, 

 entirely black. The subopercular extends along the inferior edge of the 

 opercular, tapering slightly upwards. The interopercular forms a regu- 

 lar curve immediately beneath the preopercular, and is covered with one 

 row of scales, there being a double row of these upon the subopercular. 



The dorsal fin is rather low, especially its spiny portion. Its anterior 

 margin is exactly opposite to the opercular flap. There are ten spiny 

 rays and nine soft ones, the last being double and the shortest. The first, 

 second, third, fourth, fifth, and sixth rays increase gradually in length in 

 the order enumerated ; the eighth is equal to the sixth ; the ninth is the 



