284 ostreadjE. 



fathoms; off Copenhaw Head and Loch Ranza in forty 

 fathoms. Ten miles from Fair Isle in sixty fathoms. 

 In fifty fathoms moored to stones on the Ling banks 

 forty miles to the west of Zetland. In ninety fathoms 

 off Mull (M'Andrew and E. F.). 



On the Irish Coast it has been taken in Strangford 

 Lough (W. Thompson and Hyndman) ; in Birterbuy Bay 

 on the west coast (Barlee) ; on rocky ground east of Cape 

 Clear in from forty to forty-five fathoms (M'Andrew) ; 

 and from the Nymph Bank (Warren). It ranges along 

 the Scandinavian shores to Finmark (Loven). 



The Pecten furtivus of Loven (Index Moll. Skandinav. 

 p. 31) has been dredged in Zetland; at Lerwick in 

 forty and fifty fathoms (Jeffreys) ; Loch Fyne (M'An- 

 drew) ; Galway (Barlee); and Exmouth (Clark). It dif- 

 fers from the typical striatus in being suborbicular, 

 and usually of a more opaque texture ; is either with- 

 out the aculeated striae, or has fewer and only displays 

 them fully at the sides and near the margin. Its micro- 

 scopic chasing, likewise, is much more regular (as in 

 tigrinus), and in most examples is closely decussated by 

 concentric lines. The front auricle of the upper valve is 

 somewhat incurved at its base, and above is very nearly 

 coextensive with that of the under one ; whilst in the 

 typical form the entire lateral edge of the superior front 

 auricle is comparatively straight, and above exhibits the 

 opposing auricle stretching out beyond it. All these 

 characters are rarely present in the same example, and 

 indeed blend so imperceptibly with the normal features of 

 striatus, that we are not prepared, after having observed 

 the remarkably wide range of variation permitted to its 

 British congeners, to accede at present to its separation 

 from that species. 



