'on 



V. with aftrong, Tub-triangular, yellowifii-white fhell/rTyANouLARis. 

 with a few antiquated, concentric ridges, in other re- 

 fpe6ls fmooth : umbo central, remarkably prominent? 

 and turned a little to one fide ; each fide Hoping nearly 

 equal, and forming the umbonal regions into an acute 

 angle ; under the beak a lanceolate, cordiform depref- 

 fion. Infide fmooth ; hinge very (Irong in proportion, 

 furnifhed in one valve with two flrong teeth, one 

 running backwards parallel with the cartilage flope, bi- 

 fid, or divided longitudinally; the other is triangular; 

 and near it, running parallel with the cordiform depref- 

 fion, is a ftrong, lateral lamina, of a femi-lunar Ihape, 

 the convexity inwards ; and a deep groove between that 

 and the margin : the other valve is poffefTcd of three 

 teeth, two of which greatly diverge, in order to admit 

 the triangular tooth of the oppofite valve between them ; 

 and a lateral tooth, which locks in between that and the 

 marginal edge ; the margins are plain. Length half an 

 inch ; breadth nearly the fame. 



This extremely rare fhell, was found on the coail of 



Devovjhire. 



V. with a fub-oval, fub-triangular, yeHowifli-whitf Spiniper^^ 

 (liell, v/rought with numerous, fine, concentric, paral- 

 lel, equidiftant, elevated, and fomewhat refleded ridges, 

 <about thirty fix in number: thefe ridges at the anterior 



E e e e fide. 



