ARGIOPE. 23 



abundant evidence of its having been formerly a native. 

 Dr.Turton described it in his ' Conchological Dictionary ' 

 as having been thrown up, after a severe gale, on the 

 shore near Teignmouth — a most unlikely place. Pro- 

 fessor King is said to have obtained two dead specimens 

 and a single valve off the Northumberland coast, at- 

 tached to the byssus of a Mytilus modiolus. Mr. Mac- 

 laren recorded the species as having been procured also 

 from a fisherman on the Berwickshire coast; and Capt. 

 Laskey is reported to have taken it by dredging in the 

 Firth of Forth. Capt. Thomas appears to have likewise 

 dredged valves off Berwick, and Mr. Dawson off Aber- 

 deen. In deep-sea dredging off the Shetland Isles, I 

 have more than once found single valves, and this year 

 a nearly perfect pair. Dr. Turton's specimen has a 

 very ancient aspect ; Professor King's and some of my 

 own are remarkably fresh -looking, and they may pos- 

 sibly be recent ; but I am rather disposed to think they 

 are some of the relics of the glacial epoch. The shell 

 being of a horny texture, would not be liable to undergo 

 much, if any, change while it remained under water. A 

 live specimen has never been taken, so far as I am 

 aware, anywhere south of Drontheim, where it seems to 

 dwindle in size. It is a gregarious species, and there- 

 fore common wherever it occurs. The arctic seas of 

 both hemispheres constitute its proper habitat. As a 

 tertiary fossil it is found in the Norwich or Mamma- 

 liferous Crag and later deposits. 



