MELVILL— MARINE MOLLUSCA. 125 



387. Malleus normalis, Lam. 

 Loc. Cliagos Archipelas^o. 



31. aiiatiims. Lam., is so nearly allied to this as to suggest its perhaps being only a 

 varietal form. The geographical distribution is much the same. 



•S88. Perna isognomon (L.). 

 Loc. Chagos Archipelago. 

 Only in young condition. 



389. Perna lingucBformis, Reeve. 

 Loc. Chagos Archipelago. 



390. Perna sulcata. Lam. 

 Loc. Seychelles : Praslin L 



Very imperfect and a little doubtful. 



391. Perna vitrea., Reeve. 

 Loc. Chagos Archipelago. 



P. maillardi, Desh., is nearly akin, and probably also occurs, being a well-known 

 Mauritian form. 



392. Perna vulsella, Lam. 

 Loc. Chagos Archipelago. 



Only in very imperfect condition, and therefore doubtful. The same remark will 

 apply to several others of tliis and related families. 



393. Pinna sp. 



Loc. Seychelles : Praslin I. 



Only in imperfect or non-adult condition. A ribbed, non-spinous species. 



394). Pinna, [Atrina) nigrina. Lam. 



Loc. Chagos Archipelago : Peros Banlios, Coin. 



In broken fragments. 



Family OstreidSB. 



395. Ostrea cerata, Sowb. 

 Loc. Chagos Archipelago. 



396. Ostrea hyotis, L. 

 Loc. Chagos Archipelago. 



Seychelles : Station F 2, 31 fathoms. 

 Only imperfect valves 



