202 HISTORY OF THE FISHES OF MASSACHUSETTS. 



The dorsal fin arises on a line with the origin of the orbit of the upper eye, 

 and extends to the fleshy portion of the tail. The extremities of the rays are free. 

 The first rays are quite short; those at the middle and towards the posterior 

 portion the longest ; the most posterior are the shortest rays of the fin. 



The pectorals are rounded when expanded. 



The ventrals are very small, half the height of the pectorals ; their extremities ai - e free. 



The anal fin arises just back of the origin of the ventrals, and terminates on 

 a line with the dorsal, to which it is similar in form. 



The caudal fin is large and fleshy, equal in height to the pectorals. The depth 

 of the fleshy portion of the tail at the termination of the dorsal fin is equal in 

 length to the caudal rays. The rays are deeply bifid. When this fin is expanded, 

 it is rounded at its posterior extremity ; when not expanded, it is convex, sometimes 

 almost acutely pointed at its posterior centre. 



The fin rays are as follows :— D. 89. P. 12. V. 6. A. li. C. 16. 



Length, fifteen to thirty inches. 



Remarks. The species above described must, I think, be considered the Platessa 

 ohlonga, and also the Platessa ocellaris of Dekay. This conclusion, I conceive, is 

 inevitable upon an examination of Dekay's descriptions and figures. A few obser- 

 vations upon this point may serve to settle the matter. The specimen before me 

 has ocellated spots upon its surface, an angulated caudal fin, a prominence at the 

 chin, and less than ninety dorsal rays. 



The ocellated spots would show it to be the P. ocellaris. But that species, ac- 

 cording to Dekay, has a rounded caudal fin, more than ninety dorsal rays, and a 

 prominent chin. 



The angulated caudal fin, and number of dorsal rays (less than ninety), would 

 point it out as the P. oblonga. But Dr. Dekay would lead us to infer that there were 

 never ocelli. He says, this species " is nearly uniform brown ; occasionally with spots." 

 As I have seen numbers of this species in the market at a time, they present the 

 following characters. Some have distinct ocelli distributed over the greater portion 

 of the body; while in others they are so dim as scarcely to be observed at all. 

 They all have the chin prominent. They all have an angular tail when unex- 

 panded, which is rounded when fully expanded. I have counted eighty-eight, eighty- 

 nine, ninety, ninety-one rays in the first dorsal fin. The two species of Dekay would 

 thus appear identical. 



In a specimen I received from Provincetown, in August, 18-14, both sides of the 

 fish were equally dark-colored ; the upper eye Avas situated directly upon the top of 



