62 LUCINIDiE. 



stained, somewhat concentrically in aged examples, with 

 purplish liver-colour. The dentition is quite rudimentary : 

 there is only a tubercular denticle in each valve, that of 

 the right being somewhat conical, that of the left being 

 often a callous sublaminar inward projection of the front 

 hinge-margin. There are no lateral laminae ; the ligament 

 has hitherto been taken for them. 



There exists a more elongated variety, in which, from 

 the shape, the hinder dorsal edge is almost rectilinear, and 

 rather shorter than usual, and the front one less retuse ; 

 the front extremity is more regularly rounded, and the 

 hinder angulation more central. 



So small is this curious little shell, that an individual 

 measuring the sixth of an inch in diameter, may be re- 

 garded as of large dimensions. It has hitherto been solely 

 procured on our coasts from northern stations, having been 

 dredged in thirty fathoms by Mr. M'Andrew in the Sound 

 of Skye, and by Mr. Jeffreys, at Croulin Island, which 

 lies between Skye and the mainland of Boss-shire, towards 

 Applecross, and in Loch Fyne, in mud, at from twenty 

 to a hundred fathoms (M'Andrew). The species was first 

 obtained by Captain Graves and Lieutenant Spratt from 

 Crete and the Morea, where it inhabits very deep water. 



SPURIOUS. 



L. orbicularis, Montagu. 



Venus orbicularis, Mont. Test. Brit. Suppl. p. 42, pi. 29. f. 7. — Turt. Conch. 



Diction, p. 241. 

 Oyprina „ Turt. Dithyra Brit. p. 138. — Brit. Marine Conch, p. 83. 



Cyiherea „ ' Flem. Brit. Anim. p. 446. 

 ? Lucina squamosa, Lamarck, Anim. s. Vert. (ed. Desh.) vol. vi. p. 228. 



Montagu described this exquisitely sculptured shell from the 

 single valve of an immature specimen ; we have most carefully 



