139 



ticulated very conrpicuoufly ; and, if we make allowance 

 for the various effeds of climate, it may be conjecluired 

 this is only a variety in a depauperated ftate. 



This fhell is found in great abundance on fome parts of 

 the fouth coaPi o^ Devon; and not unfrequent on that of 

 Cornwall, particularly about Falmouth; but live fnells, or 

 double valves with the epidermis on, are rare. It feldom 

 exceeds half an inch in length; and three-quarters in 

 breadth. 



3. 

 Area Noae. Xw. 5y^. p. 1140. 169. No«. 



Gmel. Syji. p. 3306. 2. Tak. 4. f. o ^ 



Chem. Conch, vii. t. 53. f. 531. a. 



Turt. Lin. iv. p. 'IbO.—Gualt. t. 87. H. 

 MufculusMatthioIi. Lifter Conch, t. 363.. f. 20S. 

 Area tortuofa. Br. Zool. No. 57. figure omitted. 



Berlqfe Corn. t. 2S. f. 15. 16. 



A. with a rhomboidal fliell, the fmaller end of each 

 valve turning inwards to meet each other, forming a fharp 

 angle, giving that end a fub-cordated appearance: the 

 umbo is placed nearefl to one fide : the apex prominent, 

 and greatly feparated by a deep fulcus, which is fmootli 

 and glofly : the ftriae that run from hinge to margin are 

 regular and Rrong ; thefe are crofled wiih fine, tranfvcrfe 

 llrije, that make the fhell elegantly reticulated : fome are 

 marked with concentric, antiquated ridges: colour ru- 

 fous-brown, lighten at the larger end. Infide whitifii or 



T 2 tinged 



