PECTEN. 277 



edge not being more than half as long again (in the adult) 

 as that of the smaller ear. The entire length of the hinge- 

 margin, likewise, is proportionately shorter than in varius ; 

 and both the external and internal surfaces of the shell 

 are in the more typical examples of a pure and uniform 

 white. 



The length of a rather large example was two inches 

 and an eighth ; its breadth was scarcely more than a line 

 greater. The proportions are very different in the young, 

 the breadth, in a specimen of half an inch wide, exceeding 

 the length by about one-fifth. 



The margins of the mantle are ample and of a plain 

 white colour : near their free-edges is a row or border of 

 very short filaments, fawn-coloured at their bases, and not 

 extended beyond the mantle-edge ; at the fixed border im- 

 mediately under the edge of the shell is a range of longer 

 and more closely set white tentacles, at the bases of 

 which are the numerous, small, black ocelli, among 

 which at intervals are narrow dusky blotches. The body, 

 foot, and branchiae are white. 



Pecten niveus lives moored to Laminariee, the old ones 

 chiefly attached to their fronds, the young ones to their 

 stalks, as we have seen when taking it alive in fifteen 

 fathoms water at Oban (M'Andrew and E. F.). It was 

 first found in the Outer Hebrides by Professor Macgil- 

 livray, who distinguished it as a species. It has not been 

 observed out of Britain. Mr. Jeffreys has taken it in Loch 

 Oarron and various other parts of the west of Scotland. 



