258 PLAGIOSTOMI. 



aboiit an inch in breadth round the pectorals, but narrower on the ventrals, and 

 still more so on the tail. 



" To recapitulate — in all the works noticed in this communication, and perhaps 

 unnecessarily so, the only figures of the torpedo corresponding exactly in propor- 

 tion with my specimen are Walsh's,* which are copied by Pennant. Those of 

 the Tremolo, illustrative of Dr. Davy's memoir, seem much the same. Two 

 desirable points are however attained — the identity of the species with Walsh's 

 specimens from the coasts of France and England, and the description of an 

 authentic native example of the fish. From Dr. Jacob I learn that two torpedos 

 were taken at the same time, about ten years ago, and he thinks oft' Dublin Bay, 

 like the present individual ; of one of these there is a cast in the Museum of the 

 College of Surgeons in Dublin ; f this I have examined ; it is 38 inches in length, 

 28 in breadth, and represents the same species as the subject of the present com- 

 munication." 



A torpedo taken by the Dublin fishermen, which weighed 14| lbs., 

 was described by Mr. M'Coy, in the 6th vol. Ann. N. H. as a new 

 sp., under the name of T. eninrf/inata. A figure of it accompanies the 

 description, and appears very different in form from other torpedos taken 

 on the coast. Dr. Ball, however, who saAv the specimen in a recent state, 

 is decidedly of opinion that it is not distinct in sp. from the others. That 

 gentleman, having obtained a specimen taken off the Dublin coast on the 

 1st Sept., 1840, remarked, in a letter to me, that he felt convinced the 

 specimen described by me and the T. einar(iinata, and also the one re- 

 cently received, were identically the same sp., and adds, " I found that 

 the slightest pressure at each side of the head was suificient to make a 

 shrugging of the shoulders, if I may so express it ; or, perhaps more pro- 

 perly, to fiex the joints of the cartilaginous arch, Avhich supports the 

 exterior of the lateral expansions or fins : this flexure produces the two 

 indentations so obvious in the specimen described by Mr. ]M'Coy, while at 

 the same time the edge all round is drawn in and thickened. Did the 

 fish die in a state of spasm, it would, I think, present the form under 

 which it has been named T. cmarginata, while in its ordinary flaccid state 

 it is T. Wdlsliii. The slight difference of position of the dorsal fin, if not 

 the result of irregularity produced in the drying of the skin, may probably 

 be also an effect of the same cause as that which produces the indenta- 

 tions and the thickening of the edges of the fish. I did not however look 

 to this point." % 



In desci'ibing Dr. Jacob's torpedo, in the 5th vol. of the Annals, I gave it 

 as my opinion, that it Avas identical with Walsh's, the onhj difference worihy 

 of note between my specimen andhis Jir/ure being that the spiracles in the 

 latter are re^rresented as notched, and, for the sake of identification, I sub- 

 sequently proposed, in my Report on the Fauna of Ireland, to name the 

 Irish specimens T. Walshii, in the then confused state of the genus. At 

 that time I was not aware of the T. nobiliana of the Fauna Italica. With 



* I do not recollect to have seen it anywhere satisfactorily stated, whether 

 individuals of the same species differ much in general outline, or whether the 

 sexes ever vary much in this respect — colour is admitted to be no character. 

 See in particular Dr. Davy, Phil. Trans. 1. c. 



t Dr. R. Ball has an excellent cast from the present specimen. 



X Dr. Ball has since confirmed his views, and ascertained that the form, which 

 not unnaturally led Professor M'Coy to consider the specimen he describes as a 

 new species, originated in its having been tied up in a handkerchief, by fisher- 

 men anxious to prevent injury. Dr. Ball, having received a specimen so treated, 

 made a cast of it, and made another when the fish became flaccid — and thus ob- 

 tained the two forms from one specimen. 



