41 



more approximate tiian the reft ; between tiie ridges fine 

 obfolete longituclinaly^/vVc are obfervable by the aid of a lens, 

 but not confpiciiou.s to the naked eye : the colour is pale 

 yellowifli-brown, with two or three broken ferruginous rays, 

 running from the umbo to the oppofite margin ; thefe in 

 fome fpecimens faintly refemble arrow-heads, pointing to- 

 wards tlie beak, fix or feven of which conftitutc a ray : the 

 limbo is pointed, and turns much to one fide, beneath which 

 is acordiform deprelfion, of a ferruginous colour: the car- 

 tilage flope is broad, and marked with tliree or four irregular 

 transverfe lines of the fame. The infide is white : the hinge 

 furniflied with three ftrong teeth in each valve, the middle 

 one of which is fub-bifid: the margin is finely crenulated. 

 Diameter about an inch ; the breadth rather exceeds the 

 length. 



This is another fpecies of Venus to which it is extremely 

 difficult to affix any synonyms. It has fomewhat the habit 

 of Venus Jlriatu/a, but more orbicular in its contour, is not 

 poflefled of thofe i\nejiria-like markings, and the ridges are 

 vaftly more elevated, thinner, and more diftant. 



We firft noticed this fpecies in a package of Scotijh fhells, 

 lent for examination from the fame quarter with the laft, 

 with an affurance that it was taken ahve, off" the ifle of May 

 in Scotland' A fpecimen, exa<5lly fimilar in every refpedl, 

 has fmce occurred on the coaft of South Devon. 



F Orsiculata. 



