PLATE LXIII. 



ARCA NUCLEUS, 



SILVERY ARK. 



GENERIC CHARACTER. 



Animal Tethys ? Shell bivalve, equivalve. Teeth of the hinge 

 numerous, inserted between each other. 



SPECIFIC CHARACTER 



AND 



SYNONYMS. 



Small, somewhat triangular, smooth, silvery within. Hinge semi- 

 circular, beset with numerous plate-like teeth. Margin finely cre- 

 nated 



Arc A Nucleus : testa oblique ovata lasviuscula, natibus incurvis, 

 margine crenulato, cardine arcuato. Linn. Sj/st. 

 Nat. p. 1143. No. 184. 



Arc a Nucleus : testa oblique ovata laeviuscula : cardine triangulari. 



Gmel. Linn. Sj/st. Nat. p. 3314. sp. 38. 



Tellina inaequilatera, margine interno minutissime dentato, sed propc 

 cardinem denticulis spissis, elatoribus, acutis, con- 

 spicua, oleagina, inrus argentea. Gua.lt 1. 

 Conch, tab. 81. fg. ft. 

 c 2 



