778 



MONOGRAPH OF THE GENUS 



ASTARTE. 



Fam. Veneridse. 



Char. Gen. Testa sequivalvis, suborbicularis, solida, clausa, lsevis 

 seu concentrice costata, epidermide induta; impressionibus mus- 

 cularibus ovatis distinctis, impressione pallii siniplici; cardine 

 dentibus duobus, validis, divergentibus, et in altera valva uno, 

 cum vix secundo ; ligamento elongato externo. 



This genus, the Crassina of Lamarck, is distinguished by the 

 almost constant presence of a dark chestnut-brown epidermis on 

 an otherwise colourless surface, which is generally corroded at the 

 apices. The form is flatfish, rounded, and more or less inequi- 

 lateral; the impressions are deep, and the pallial scar simple; 

 the inner surface is thickened, so as to produce great solidity in 

 advanced specimens; the external ligament is long and tumid; 

 the teeth are diverging and strong, two in one valve and one in 

 the other, with sometimes a rudimentary second ; the inner ven- 

 tral margin is sometimes crenated, and sometimes (even in the 

 same species ?) smooth. In all the specimens of all the species I 

 have examined, excepting perhaps the dubious A. triangularis, 

 there is a similarly excavated, elongated, and smooth character in 

 the dorsal area and lunule ; muscular impressions deep, with the 

 pallial line simple. 



1. Astarte sulcata (pi. clxvii. f. 1, 2, 3), La Costa. Pec- 

 tunculus sulcatus, Brit. Conch, p. 192. Crassina Daumonieusis, 

 Lamarck, An. s. vert. ed. 2. vol. vi. p. 257. Venus sulcata, Tart. 

 Crassina Scotica, Turt., Dithyra Brit. p. 130. pi. 11. f. 3, 4. 

 Crassina sulcata, Turt., Dithyra Brit. p. 131. pi. 11. f. 1, 2. 

 Astarte Damuoniensis, Soiverby, Genera of Shells, f. 1, 2, 3. 

 Venus crassatella, I)e Blainville. Crassina semisulcata. 



