350 VENERID^. 



and the same numerous microscopical striae which have been 

 already noticed in several species of Venus : colour yellowish- 

 white with a golden tint, mostly variegated by several broken 

 rays, or marbled with zigzag streaks or blotches of reddish- 

 brown or light purple, sometimes of a uniform pale yellow or 

 milk-white: epidermis horny, usually retained only on the 

 lunule and corselet : margins obliquely rounded in front, and 

 more sharply curved on the anterior side, produced or wedge- 

 shaped at the posterior end, which is also curved with a gradual 

 and rounded slope on the dorsal or ligamental side: beaks 

 small, slightly recurved, and close together ; umbonal area ra- 

 ther prominent : lunule lanceolate, not deep but distinctly exca- 

 vated and denned by a separating line or groove ; it is usually 

 stained with purple or of a darker hue than the prevailing 

 colour ; the lips do not project : corselet narrow and indistinct, 

 sculptured in the same way but not so strongly as the rest of 

 the shell : ligament rather narrow, yellowish-brown, wholly ex- 

 posed, contained in a groove between the dorsal margin and 

 the hinge-line, which is obtusely angular: hinge-plate short, 

 thick, and flexuous : teeth, in the right valve three cardinals, 

 of which those in the middle and on the anterior side are 

 erect, double, and but slightly divergent, and the posterior 

 is smaller and triangular ; the left valve has the same number 

 of cardinals, but the smallest is on the anterior side, and the 

 other two are erect, double, and nearly straight ; laterals on 

 the anterior side sunken but distinct: inside rather glossy, 

 tinged with orange and often having a purple stain at the 

 hinge : pallial scar broad and iridescent, deeply sinuous on 

 the posterior side : muscular scars triangular, large, and deep. 

 L. 1-3. B. 1-5. 



Var. 1. quadrata. Shell compressed, and having a squarish 

 outline owing to the dorsal margin being straighter. 



Var. 2. ovata. Shell more compressed and produced at 

 each end. 



Habitat : Southern and. south-western coasts of 

 England and Ireland, as well as the Channel Isles, in 

 sandy gravel, at from 3 to 18 fathoms. Cullercoats and 

 Whitburn (Alder, fide J. H. F. and Abbes) ; Tenby 

 (Lyons) ; Pwllheli (M'Andrew) ; Belfast (Hyndman) ; 

 Lough Strangford (Dickie) ; Clyde district (Smith and 

 others) ; Jura Isle (Bedford). It occurs in a fossil state 



