PLATE XXVI. 
rally believed, that this fish casts off and renews its large tuberciv 
lated spines every year, and that the places from which they have 
fallen may be easily perceived bv the whitish marks that remain m 
the skin. When the ground colour of the back is a lightish ash, 
and the round whitish spots are each distinctly encircled with a ring 
of black, the upper surface of this common fish has a pretty orna- 
mented appearance. The under side is pure white with only a few 
spines. 
The Thornback is taken at most seasons, but in the greatest abun- 
dance in the spring and summer, because they approach the shores at 
those times in vast numbers to deposit their eggs among the weeds. 
The eggs of these fish bear a strong resemblance to those of the Shark 
tribe, having a quadrangular, black, and horny shell, but the cor- 
ners do not terminate in long filaments as in those of the Shark. 
Like the other kinds of flat fish, the Thornback frequents sandy 
shores, and feeds on all kinds of small fish and worms, both of the 
naked and shelly tribes. 
I 
The amazing size to which these fish sometimes grow is almost 
incredible ; a ray supposed to be of this species was captured near 
the island of St. Christopher’s, in 1 634, that measured twelve feet 
in length ; and Gmelin informs us, that this species does sometimes 
grow to that size. On the coast of Norway they are taken in vast 
quantities : the flesh the natives eat, either fresh or salted, and from 
the liver extract an oil for burning in their lamps, or other domestic 
purposes. The flesh of the Thornback, is thought, in England, in- 
ferior to the Skate, and is not unfrequently sold for it, by the Lon- 
don fish-mongers. 
