VENUS. 331 



Var. compta. Shell smaller, more elongated, with coarser 

 ribs and stronger teeth. Artemis compta, Lov.Moll.Scand.p.39. 



Habitat : Sand, sometimes mixed with mud, on every 

 part of the British coasts, from low-water mark to 

 90 fathoms, occasionally associated with the last species. 

 Var. compta. Single valves only, from Skye (Barlee) ; 

 Shetland (J. G. J.). V. lincta is fossil in all our upper 

 tertiaries, from the so-called "alluvial" stratum in Belfast 

 Harbour and the boulder-clay of Wick to the Red and 

 Coralline Crag, as well as in the redeposited Crag-bed 

 of Aberdeenshire. Iceland is its most northern known 

 boundary, and the iEgean and both sides of the Medi- 

 terranean the most southern. Philippi noticed its occur- 

 rence in the South- Italian tertiaries. 



Lister, in his 'Historia Conchyliorum/ well distin- 

 guished this species from V. exoleta, as "rostro pro- 

 duction, capillaceis fasciis donatus." It is smaller, more 

 convex and glossy, the laminar ribs are much more 

 numerous, the posterior side is somewhat flexuous, it is 

 destitute of the coloured markings peculiar to the other 

 species, and the umbones are more prominent. The 

 small anterior teeth have more the appearance of short 

 laterals, and may be analogous to those of Circe. My 

 largest specimen does not much exceed an inch and a 

 half in length. Monstrosities sometimes occur : a speci- 

 men now before me is nearly globular, with consequently 

 a much more abbreviated lunule ; and Mr. Norman pos- 

 sesses one which is remarkably inequivalve. 



The description of V. lupinus in the tenth edition of the 

 ' Systema Naturae 5 (although not of the variety "maculis 

 griseis") may possibly have been intended for V. lincta; 

 but no locality is assigned to it. Poli adopted the 

 former name for the present species ; Lamarck called it 

 Cytherea lunaris ; Turton V. sinuata ; and Risso Arcto'e 



