V 



FAMILY 8. CONCHACEA (MARINA). 73 



catis, in valva dextra ; dentibus, altero distincto, altero obsoleto, in 

 sinistra. Impressiones musculares duge, quorum una bipartita. 



Sowerby was the first to introduce this genus under the above title ; 

 Lamarck afterwards described it under that of Crassina ; the former 

 therefore has the priority. The latter author placed it, though not with- 

 out some indecision, in his family of the Nymphacea ; but upon noting 

 the affinity of the shell of Astarte with that of Cyprina and Venus, the 

 propriety of its removal to the family of the Conchacea will be readily 

 admitted. 



The shell of Astarte may be described as being- nearly orbicular but 

 somewhat transverse, equivalve, inequilateral, and covered with a brown 

 epidermis. The hinge consists of two divergent teeth in the right valve; 

 with one distinct and one obsolete tooth in the left. One of the muscular 

 impressions is bipartite, and the ligament is external. 



Example. 



PI. LXVI. Fig. 1 to 3. 



Astarte Damnoniensis, Sowerby, Genera of Shells, No. 4. 

 Venus Damnoniensis, Montague. 

 Venus crassatella, De Blainville. 

 Crassina Damnoniensis, Lamarck. 



VENUS, Linnaeus. 



Testa aequivalvis, insequilateralis, suborbicularis, subglobosa, extus ple- 

 rumque rugosa, rard laevis, undique clausa. Dentes cardinales 

 plerumque tres in utraque valva ab umbone divaricati, interdum 

 contigui. Impressio muscularis pallii sinu mediocri. Ligamentum 

 externum. 



The Linnsean Veneres have been variously distributed ; and although 



n 2 



