88 PECTINID.E. 



perforated in the centre and strengthened by a thick rib : in- 

 side pearly, closely granular, slightly impressed by the ribs ; 

 front margin scalloped or fluted in the young and very thick 

 in the adult: muscular and pallial scars indistinct, especially 

 the former. L. 1*6. B. 1. 



Var. tenera. Shell smaller, narrower, and more depressed, 

 with fewer ribs. L. tenera, Turton in Zool. Journ. ii. p. 362, 

 t. xiii. f. 2. L. 1. B. 0-6. 



Habitat : Hard ground, in 12-40 fathoms, very com- 

 mon in the West of Scotland; Orkneys (Thomas); 

 Aberdeen (Macgillivray) ; north-east coast of Ireland 

 (Portlock, Hyndman, and Waller) ; Anglesea (M f An- 

 drew and Forbes) ; Isle of Man (Forbes) . A specimen 

 from the last- mentioned locality, which I received from 

 the late Professor Forbes, is intermediate between the 

 typical form and the variety, as well as a specimen 

 which Mr. W.W.Walpole sent me from Killiney Bay, 

 near Dublin. As an upper tertiary fossil it has been 

 noticed by the late Mr. W. Thompson and Mr. Grainger 

 in a bed of blue clay at Belfast, and by Mr. Searles 

 Wood in the Coralline Crag at Ramsholt. The variety 

 is found on the southern coast of Cornwall and in the 

 Channel Isles. It is not uncommon at Herm, under 

 large stones, at low- water mark. The range of this 

 variety southward is very extensive, having been re- 

 corded by numerous authors in different parts of the 

 Mediterranean, iEgean, and North Atlantic seas, as 

 far as the Canary Isles, Madeira, and the Azores, at 

 depths of 0-50 fathoms. The typical or northern form 

 inhabits the coasts of Norway and Sweden, in 4-30 

 fathoms. Malm found a specimen in the stomach of a 

 cod-fish. 



In Mr. Norman's interesting notices of the Clyde 

 Mollusca (published in the c Zoologist' for 1858) is the 

 following : — " Nothing can be more lovely than the ani- 



