320 TELLINIDiE. 



ing ordinarily in tlie adult but little convexity of outline. 

 The beaks are depressed and minute, and scarcely incline 

 to eitber side. The saiFron-coloured cartilage is situated in 

 rather a large subtrigonal spoon-shaped projecting recepta- 

 cle ; on either side of this (in the right valve only) is an 

 approximate sublateral lamina, the front one of which is the 

 longer. The valves gape in a remarkable degree at each 

 extremity. 



The animal is white, ovate and compressed. The edges 

 of the mantle are free and finely fringed. The anal siphon 

 is dusky, and, as if invested with a brownish corrugated or 

 ringed epidermis. The branchial one is transparent, and 

 presents a reticulated appearance. The foot is linguiform 

 and very changeable. 



It lives buried in slimy mud in various depths, from six 

 to one hundred fathoms, and appears to be a species of 

 boreal origin, occurring chiefly in the neighbourhood of the 

 pleistocene deposits of Scotland, and in peculiar localities in 

 the Zetland isles, and on the west and south of Ireland. It 

 was first found by Mr. Ball, Mr. Thompson, and Mr. 

 Forbes, in the bay of Killery, in Connemara, and after- 

 wards by Mr. Thompson, in six fathoms, in Strangford 

 Loch. As it is a rare British shell we mention all the other 

 localities ; Loch Fyne in fifty fathoms ; Dunstaffhage ; 

 Armadale in Skye, in from fifteen to forty fathoms. St. 

 Magnus bay twenty-one miles east of Brassay in seventy 

 fathoms ; and twenty-five miles east of Noss in one hundred 

 fathoms, all in Zetland (Mac Andrew) ; Deal Voe, Zetland 

 (Jeffreys) ; Birterbuy bay, in Connemara (Barlee and 

 Farren) ; and Cape Clear in sixty fathoms (Mac Andrew). 



It is essentially a northern species, and is recorded as an 

 inhabitant of the Norwegian seas (Liiven) and the Straits 

 of Oresund (Oersted). 



