128 TOKPKBO. 



Toiyedo Galvanii, Risso; pi. 3, f. 3. Une tache. T. uni- 



maculata. 

 " nohiliana, Yakrell; vol. ii, p. 546. Walsti's ex- 



periments were made on this species. 



Although the figures of these fishes in books of Natural 

 History are in g^ leral sufficiently characteristic, there have 

 usually been defects, the cause of which may properly form a 

 portion of their history. 



It is only for a short time after the fish has been taken from 

 the water that the disk preserves its shape and dimensions. 

 Soon after death a shrinking takes place on the upper surface; 

 by which the plumpness of its appearance is diminished, and 

 the borders become contracted; so that the lower surface 

 gradually curls upward, and occupies the margin to the extent of 

 several inches. But if it happen that the body has been placed 

 in a position by which its parts have sustained a strain, the 

 proportions become stretched into an unnatural shape, much 

 unlike that which it bore when alive. Risso's figures appear 

 to have been drawn from examples which had been thus dealt 

 with; and although boasted of by him, are by far the worst 

 anywhere to be found. The particular changes thus referred 

 to are noticed by Mr. Dillwyn, in his "Fauna of Swansea:" 

 "When alive the length was found to be forty-one inches 

 and a half, the greatest breadth twenty-nine inches and a half; 

 the breadth of the caudal fin at its extremity nine inches, and 

 the weight above forty-four or forty-five pounds. On the 

 following day it measured forty-two inches by thirty, and it 

 then weighed forty-three pounds and a half. In stuffing the 

 specimen the length, to my surprise, has considerably increased, 

 though the other dimensions remained nearly unchanged, and 

 now the extreme length is forty-nine inches; the upper lobe 

 twenty-four inches, the lower lobe ten inches and a half, the 

 tail eight inches and a half, and the caudal fin six inches long. 

 The breadth or greatest diameter of the upper lobe is thirty 

 inches, and of the lower lobe fifteen inches, and the caudal fin 

 has contracted at its extremity to be only eight inches broad." 



Our description is from an example taken in a trawl a little 

 on the outside of the Breakwater in Plymouth Sound. The 

 length two feet six inches; form of the disk nearly circular; 



