432 VENERID^. 



the lower corners of the shell are perfectly free from angu- 

 lation. The dorsal edge, whose declhiation exceeds that of 

 exoleta, is in front short, rather strongly sloping, and with 

 its general inclination, though not its actual outline, in- 

 curved ; behind it is far more elevated, curved, and ranges 

 from very moderately to decidedly sloping. There is a 

 manifest, although slight, flattening (but no excavation) of 

 the hinder dorsal surface. 



iBoth sides are somewhat angulated above, and are 

 rounded below ; the front and hinder edges are more or less 

 convex. The ligament, though plainly visible, is sunken ; 

 the umbones are very prominent, and bend considerably 

 forward ; in front of them is a large heart-shaped deeply 

 impressed lunule, with pouting lips, which is rarely if ever 

 stained with any colouring matter. The beaks are very 

 acute, and rarely adorned with painting different from that 

 of the umbones ; but in a scarce northern variety are 

 purple. The interior is of an uniform white, and is for 

 the most part devoid of lustre ; its margin, which is very 

 slightly flexuous, is perfectly free from crenation. 



This species never attains to the dimensions of the pre- 

 ceding, its diameter rarely measuring an inch and a third. 

 From the greater declination of the dorsal lines the 

 adult shell appears to taper in some degree towards the 

 umbones. The exquisite delicacy and crowded disposition 

 of its concentric lines, the absence of coloured markings, 

 and the flattening of the hinder dorsal surface, enable us 

 with facility to distinguish it from exoleta. 



The Artemis lincta is nearly equally common with its 

 British congener, though not always occurring in the same 

 localities. It has as great a range in depth, extending 

 from near low-water mark in some places to as deep 

 as sixty fathoms in others. As instances of its distribu- 



