Storefs Synopsis of the Fishes of North America. 263 



History." Mr. Ayres afterwards found an entire specimen at Brookhaven, Long Island, 

 and called it M. acuta ; this name, however, he withdrew, and allowed mine the priority. 

 As, however, he has fully described from a recent specimen what I merely named from frag- 

 ments of one, I feel that his name should be retained, and mine erased from the list. The 

 remarks of my lamented friend, Rev. Mr. Linsley, of Connecticut, contained in his " Cata- 

 logue of the Fishes of Connecticut," upon the impropriety of considering the number of 

 caudal spines as specific characters, are very just, and conclusively show the impropriety of 

 my specific name. 



GENUS IV. AETOBATIS, Mhller. 

 Have no marginal teeth ; the jaws support only a single row of broad dental 

 plates. In the upper jaw, these plates are arched, with the convexity turned 

 forwards ; in the lower jaw, they pass straight across, with the extremities 

 only a little bent backwards. The upper jaw is shorter and more curved than 

 the lower one, the anterior extremity of which projects beyond the upper jaw, 

 and can be used like a spade in digging out shell-fish, &c, from the sandy 

 bottoms frequented by these Rays. 



1. Aetobatis guttata, Shaw. 



Subrhomboidal. Snout spatuliform. Above light brown, with regularly distributed, nu- 

 merous yellowish-white ocelli ; beneath white. The tail, which is nearly four times as long 

 as the body, is small at its origin, and terminates in a mere thread. In the dried specimen, 

 a deep concavity upon the top of the head, between and back of the eyes, dilated anteriorly. 

 Adult very large. 



Length of body, 17 inches ; of tail, posterior to dorsal fin, -15 inches. Greatest width of 

 body, across pectorals, 20 inches. 



Porto Rico, Storer. 



Raia guttata, .Suaw's Gen. Zoifl., v. p. 2S5, pL 112. 



GENUS V. RHINOPTERA, Kt in.. 

 Have the muzzle divided into two short lobes, under which are two similar 

 ones. 



1. IMiinoptera quadriloba, Lesueur. 



Body rhomboidal, elevated along the dorsal line. Olive-brown above, beneath white. 

 Pectorals acute. Tail slender, longer than the body. 

 Length, 3 feet. Width, 2 feet. 



