34 NOMENCLATURE. 



MULTIVALVES. 



Basis. B^se; in Chiton and Lepas that part of 

 the shell which is affixed to extraneous bo- 

 dies, either with or without a Peduncle ; in 

 Pholas, as in Bivalves, the part of the mar- 

 gin opposite to the summit of the beaks. 



LiGAMENTUM. Cartilage J the membrane which 

 connects the valves. 



LiMBUS. Border ; the marginal membrane of 

 Cliiton. 



Oi'ERCULUM. Operculum ; in Lepas, the lid 

 which closes the vertical aperture, consist- 

 ing usually of four triangular valves. 



Pkdunculus. Peduncle; the tubular support 

 of certain Lepades. 



coriaceiis. Coriaceous ; like leather. 



Valv.*;. Valves. 



dorsales. Dorsal ; the solitary valves in the com- 

 pressed quinqucvalve species of Lepas. 



succeniunaicc. Accessory; those smaller irregular 

 valves which are annexed to the hinge of 

 the Pholadcs. 



