NUCULA. 225 



margins of its disk so coarsely serrated ; creuations are, 

 however, more numerous. 



This is essentially a Northern species, and common only on 

 the coasts of Scotland, and the north-east of England. It 

 inhabits deep water on muddy or sandy bottoms, and is a 

 favourite food for haddocks. The most southern locality 

 of which we have a note is " Tenby," communicated by 

 Mr. Jeffreys, on the authority of Dr. Goodall. The only 

 other English localities are Scarborough (Bean), and the 

 coast of Northumberland, where ii is frequent in the coral- 

 line zone (Alder). In Scotland it occurs in the Clyde 

 district, and the Hebrides in many localities, where we have 

 taken it alive in depths from forty to one hundred 

 fathoms : also in Zetland in sixty and eighty fathoms 

 (M 'Andrew and E. F.) 



The more trigonal and convex variety has been taken by 

 Mr. Jeffreys in one hundred fathoms, fifty miles east of 

 Lerwick, and ten miles from the same part of Zetland in 

 fifty fathoms. " Alive in forty fathoms, fine sand, about 

 five miles off the Ord Head, Caithness, associated with 

 Virgularia, Solen pellucidus, 3IonfacutcE, Lucina flexuosa^ 

 &c"" (Thomas). Capt. Laskey found it off the entrance 

 of the Frith of Forth in considerable numbers. In Ireland 

 it has been taken at Portmarnock, near Dublin, by Mr. 

 Warren. 



This shell appears first as a fossil in the red crag, and 

 occurs in the mammaliferous crag of Southwold (S. V. 

 Wood), and the pleistocene beds of the Clyde (Smith), and 

 Ireland (E. F.). It distribution as a living species is ex- 

 tensive, ranging through the Boreal and Arctic seas, and 

 round to the coasts of Massachusetts. 



VOL. II. 



