PLATE LXXVIII. 



ARCA CAUDATA. 



TAILED ARK SHELL. 



GENERIC CHARACTER. 



Animal Tethys. Shell bivalve equivalve. Teeth of the hinge 

 numerous, inserted between each other. 



SPECIFIC CHARACTER. 



Oblong oval, one end rotundated, the other produced or length- 

 ened out, angulated, and truncated at the end. 



Arca CAUDATA : testa oblongo ovall anterius rotundata posterius 

 elongata angulata, apice subtruncata. 



Very rare, and not hitherto described as a British species. Found 

 on the Kentish coast. 



