VENUS. 343 



lunule lance-shaped, well defined, sculptured like the rest of 

 the surface, usually of a darker hue ; lips prominent : corselet 

 wanting : ligament narrow, horncolour, wholly exposed : hinge- 

 line gently curved : hinge-plate broad and even : teeth, in the 

 right valve three divergent cardinals, the middle one being the 

 shortest and double, and the others triangular and laminar, 

 the anterior is the highest and longest, and the posterior nearly 

 parallel with the hinge-line ; in the left valve are also three 

 cardinals, the middle one triangular and slightly cloven, the 

 anterior the smallest, and the posterior cloven and irregular ; 

 laterals indistinct : inside dull chalky-white, with often a lilac 

 stain on the umbonal part or posterior side ; margin finely 

 notched on all sides : pallial scar polished and iridescent, an- 

 gularly sinuous on the posterior side: muscular scars large, 

 roundish-oval. L. 0-55. B. 0-7. 



Yar. 1. lutea. Shell plain yellowish or white. 



Yar. 2. trigona. Shell triangular and having only about 

 twenty ribs. 



HABITAT : Rather common on a sandy bottom and 

 among nullipores, in the laminarian, coralline, and deep- 

 sea zones. Dr. Leach says that he found it in Dingle 

 Bay, Ireland, "very abundantly under the sand at the 

 lowest tide " ; and Capt. Beechey has dredged it off the 

 Mull of Galloway in 145 fathoms. The first variety is 

 from Guernsey, Exmouth, west coast of Scotland, and 

 Shetland, in 15-100 fathoms ; and the second has been 

 taken by me at Guernsey. V. ovata occurs in all our 

 upper tertiaries, and the variety trigona in the Coralline 

 Crag. It has been observed on every coast between 

 Finmark and the Morea, at depths varying from 6 to 135 

 fathoms. Subapennine beds (Brocchi) ; South-Italian 

 tertiaries (Philippi) ; upper miocene strata near Antibes 

 (J. G. J.). 



M. Gay finds these shells in the stomachs of Trigla 

 gurnardus at Toulon. The colour of some specimens 

 from the deepest water within the line of soundings on 

 our northern coasts is quite as bright, but not so varie- 



