48 



GuiXEEXsis. Vemis Guiaecnsis, Gmcl Si)>il. p. 3207. — Born. Mm. t. 4. f. 3. 



Chnii. Conch, vi. t. ,'J0. f. 31 1-31 i3. 



Shell fiib-CDrclate,wrouglit with numerous clofe, regular, 

 Iharp ridges. The contour of the flvell greatly refembles 

 Venus pidtula : the colour is cinereous-white, with two or 

 three rays of purplifli -brown running from the umbo, that 

 near the hinge is broad : the cordiforni and cartilage depref- 

 iions are botli purple. In fide very white, inclining to purple 

 on the margin behind the hinge : the hinge is very compli- 

 cated ; in one valve there arc three teeth, one of whicli 

 Hands tranfverfe ; the other has alfo three teeth, befides a 

 prominency on the fide of the cavity that receives the tranf- 

 verfe (ooth of the otlier valve : the mcrgin is plain. Length 

 an inch and a quarter ; breadth one inch and a half. 



This rare fpecies, though fo much like Venus Jlriatida m 

 fliape, differs from it in many particulars ; tlie teeth are 

 eflentially different, and the want of the crenulated margin, 

 and (Iricc-like markings, at once diflinguiflies it, independent 

 of the ridges being much thinner and more elevated. Tlie 

 plain margin alfo points out an obvious diftin6lion between 

 it and Venus rejlexa. 



The fliell from which the above defcription is taken, to- 

 gether with a fmaller fpecimen, was dredged up off 5"/. 

 Abb's Head, in the Frith of Forth, by Mr. Laskey. 



SuBSTRiATA, Shell tranfverfely ovate, fub-pellucid, white, concentri- 

 Tab. SS. f. 6. cally wrinkled, and obfoletely wrought with undulated, 



longitudinal 



