the Fishes of Massachusetts. 187 



farther back, upon the sides and benealh, numerous smaller 

 spines were scattered throughout its whole extent : the under 

 edge of the tail was bordered by a fleshy membrane which 

 commenced anterior to two very strong spines situated upon 

 the dorsum of the tail — the anterior one is five inches long, 

 one half inch wide at its base, and pointed at its extremity : 

 the posterior spine is less than half the length of the former : 

 both of the spines armed upon the edges with numerous re- 

 troverted teeth. 



I have also received from Dr. Yale another tail of a Try- 

 gon which I suppose to be of this same species. It is forty 

 inches in length, and differs in no important particular from 

 the preceding one, save in the proportions of the serrated 

 spines, which are of equal length — both being four inches 

 long. I suppose these detached portions to belong to that 

 species called Raia centroura, Prickly-tailed Sting-Ray, by 

 Mitchill in his '' History of the Fishes of New York." 



To Dr. Yale I am also indebted for the tail, and portions of 

 the jaw, of a species of the genus Myltobatis, Dumeril. In 

 this genus, " the jaws are furnished with broad, flat teeth, 

 placed like flags in a pavement, and diifering in size according 

 to the species : the tail is extremely long and slender, termi- 

 nating in a point, and is crowned, like that of a Trygon, with 

 a strong spine notched on both sides, supporting near its base, 

 and before the spine, a small dorsaL" 



I know of but one American species having been describ- 

 ed — Raia quadriloba, Lesueur. That was taken at Egg 

 Harbor, New Jersey, and was evidently not the species we 

 are now considering. The jaws of our species, are furnished 

 with rows of smooth, flat, elongated plates, with rhomboidal 

 plates exterior to these. The tail, which is thirty inches long 

 from the anus, is of a dirty brjwn color, and perfectly 

 smooth : in its present dried state, it is an inch and a half 

 wide at its origin, and tapers to a point. Two inches back 

 of the anus is situated the dorsal fin, which is subtriangular, 

 and a little more than an inch long. At the posterior extremity 

 of the dorsal fin is a strong naked spine, three inches in 

 length, closely serrated upon its sides, from its base nearly to 



