THORNBACK. 



Raja Clavata. JR. cinereo-Jlavescens, rostra suhacuto, carport 



aculeis spar sis clavatis, serie dorsali unica. 

 Yellowish-cinereous Ray, with subacute snout, scattered clavat- 



ed aculei on the body, and a single row down the back. 

 Raja clavata. K. aculeata, dentibus tuberculosis, cartilaginti 



transversa abdominali. Lin. Syst. Nat. 

 Raja clavata. Rond. Gesn, Will, Raj, SfC. 

 Thornback. Penn. Brit. ZooL 



This species grows to a very considerable size, 

 though rarely equal in magnitude to the Skate : in 

 its general appearance it resembles that fish, but 

 is somewhat broader in proportion, and is easily 

 distinguished from the Skate by the very strong, 

 curved spines with which its upper surface is 

 covered : these are most conspicuous down the 

 middle and on each side of the back, where four or 

 six, of much larger size than the rest, are generally 

 jseen; the remaining parts being furnished with 

 many scattered spines of smaller size, intermixed 

 with still more minute ones, and the whole skin is 

 of a rough or shagreen-like surface : the back is 

 marked with an uncertain number of pale or 

 whitish, round spots, of different sizes, and which 

 are commonly surrounded with a blackish or dark- 

 coloured edge: these spots are said to be caused 

 by the shedding of the spines at different intervals; 

 along the middle of the back runs a single row of 

 strong spines, continued to the tip of the tail ; and 

 it often happens that there are three, or even five 

 rows of spines on this part, as in the figure given 



