Class IV. THORNBACK RAY. 123 



disposed along the back and tail. In a large Descrip- 

 one we saw, were three rows on the back, and 

 five on the tail, all inclining towards its end. 

 On the nose, and on the inner side of the fore- 

 head, near the eyes, were a few spines, and 

 others were scattered without any order on the 

 upper part of the pectoral fins. The mouth 

 was small, and filled with granulated teeth ; the 

 upper part of the body was of a pale ash color, 

 marked with short streaks of black, and the 

 skin rough, with small tubercles like shagreen ; 

 the belly white, crossed with a strong semilunar 

 cartilage beneath the skin ; in general the lower 

 part was smooth, having only a few spines on 

 each side. The young fish have very few 

 spines on them, and their backs are often 

 spotted with white, and each spot is encircled 

 with black. 



This species frequents our sandy shores, is 

 very voracious, feeds on all sorts of flat fish, is 

 particularly fond of herrings and sand eels, and 

 sometimes eats crustaceous animals, such as 

 crabs. Thornbacks sometimes weigh fourteen 

 or fifteen pounds, but with us seldom exceed 

 that weight. , 



They begin to generate in June, and bring 

 forth their young in July and August, which 

 (as well as those of the skate) before they are 



