CYPRICAEDIA. 333 



being radiately ribbed ; as regards the second^ in being of 

 an opake-wliite nature, with little or no indication of epi- 

 dermis. Among such as belong to this small genus of 

 thirteen species, there are three which differ materially from 

 their brethren in their habits, inasmuch as they live im- 

 bedded in shells or large masses of madrepore, after the 

 manner of the Lithodomi : the shells, also, are not much 

 unlike them in form and general appearance. They are of 

 a peculiar tenuity and transparency, and do not present that 

 posterior angulation which is so prominent in the typical 

 species. 



Of these, the Coral-eating CypncarcVia (C. coraUiojjhaga) 

 is found at the depth of five fathoms, piercing and imbedded 

 in the Avicula 7nargantifera, at Lord Hood^s Island, Pacific 

 Ocean, and within masses of coral and madrepores in the 

 West Indies ; such, also, is the haunt of the Laminated 

 {C. laminata). The C. deciissata is likewise one of the tere- 

 brating species ; but the habitat is, as yet, undiscovered. 



A surpassing delicacy of the ridges is characteristic 

 of the Mesh-tinted Cypricardia [C. incarnata), discovered 

 under a stone at low water in one of the Philippines. In- 

 stead of looking as if raised upon the surface, they appear 

 like undulated rays of light. 



