118 PROCEEDINGS OF THE ACADEMY OF 



the Black Bass of the Saint Lawrence, " the " Grystes nigricans of Agassiz. " 

 Such doubts deserve no consideration, as there are none of its being at least 

 the congener of Morone americana. 



As to the Labrax pallidus, there is a greater discrepancy in the descrip- 

 tion of it as compared with that of the Labrax r u f u s . It is said that in the 

 former, the opercle has " a single flat spine, and a pointed membrane extend- 

 ing beyond it," while the generic characters given by Cuvier to the genus are 

 retained, one of which is founded upon the presence of "two points on the 

 opercle." The statement that Labrax pallidus has but one spine is pro- 

 bably due to a misapprehension of Dekay. In the Morone americana 

 there is one acute point terminating the opercle, above which is an emargina- 

 tion separating it from a more obtuse or rounded process, which in one case 

 has been regarded as a spine, and in the other has not. It is impossible to 

 believe that two fishes of this genus so nearly resembling each other, should 

 so differ in the developement of the opercular spines. 



Another distinctive character is said to exist in the first ray of the posterior 

 dorsal, which is " nearly as long as the second." Was not this relative differ- 

 ence in the proportions of the rays the result of injury to the tips of the suc- 

 ceeding soft ones ? As a third character, it is mentioned that the body is 

 " much compressed." From the figures of Labrax rufus and Labrax pal- 

 lidus, it would appear that any difference in height was rather in favor of 

 the former than of the latter. No mention is made in the description, of the 

 color of the fins of Labrax pallidus, but from the figure it would appear 

 that the pattern is nearly the same in that species as in Labrax rufus, but 

 the shade is lighter towards the borders of the dorsal and anal. This differ- 

 ence is too trivial to be accepted as specific, and if the above conjectures as to 

 the nature of Dr. Dekay's statements are correct, the Labrax pallidus 

 must be regarded as a mere s vnonyme of Morone americana. 



Morone interrupta Gill. 

 Synonymy. 



Labrax chrysops Girard. General Report upon the Zoology of the several 

 Pacific Railroad routes, Ichthyology, p. 29. 

 non Roccus chrysops Gill. 



The form of this species scarcely differs from the Morone americana, 

 the chief difference existing in the more gradual declination of the dorsal out- 

 line to the end of the second dorsal fin, and the greater inequality of the an- 

 terior and posterior portions of the caudal peduncle. The greatest height of 

 the body equals three-tenths of the length from the snout to the concave mar- 

 gin of the caudal fin ; of that length, the head forms almost three-tenths, 

 being not much less than the height of the body, and the caudal fin, at its mid- 

 dle rays, equals half of the height of the body. The caudal fin, when expanded,^ 

 is emarginated and its angles rounded ; the shortest rays equal three-fifths of 

 the length of the longest. 



The dorsal fin commences at a vertical intermediate between the bases of 

 the pectoral and ventral fins, and is of a triangular form, the fourth ray being 

 the largest, and equalling the length of the pectoral fin ; the spines have the 

 same form and arrangement as those of Morone americana. The second 

 dorsal is connected by a membrane as in Morone americana; its spinous 

 or first i ay is little more than half the length of the first articulated one, which 

 itself is nearly as long as the fourth dorsal spine ; the fin thence decreases in 

 height towards its last ray, which is shorter than its spinous one. 



The anal fin commences under the fourth or fifth articulated ray of the 

 second dorsal, and about four of its rays are posterior to the termination of 

 that fin ; the first spine is short and robust ; the second at least twice as long 

 as the first, compressed, and very strong ; the third is as long or longer than the 

 second, but much more slender. The first articulated ray of the anal is 



[April, 



