CONCHOLOQY. 1-7 



Ja.viea. 



SlioU iiiequivalvc, libbed, the upper valve llattcneil. Auiielus sulieqiial. 



* ,, HiSTRioxicrs, Gmel. 



* „ prxiDATUs, Bom. 



Amussium. 



Shell subequivalve, orbicular, thin, gaping, smooth. 



* ,, ri-EDEONECTKS, L. 



Faiiiilij Vulsellidse. 

 Vulsella. 

 Anterior adductor muscle none. 



* ,, LiNGUA-FELis (?), Reevc. 



Fa mill/ Aviculidse. 



Sliell incipiivulve, pearly within, with a prismatic cellular layer, and nacreous 

 lustre. 



Meleaorixa. 



Shell orbicular. Right valve with a byssal sinus. Hinge linear, edentulous. 



* ,, MAEOAEITIFEllA, L. 



The 'Fearl oyster' occurs aloug the coast of .Yrakan, and 'banks' of them 

 would no doubt be found if proper search was made. Any shell, however, whose 

 interior coat displays a fine nacreous lustre is capable of producing pearls, Avhich 

 are mei-ely a deposit of the lustrous lining material of the shell round some foreign 

 and oii'euding object, and in Europe pearls are found in the river mussel M. 

 maryai itifrra, L. Black pearls are occasionally produced by a species of Pinna, 

 and a pink pearl by the giant stromb of the West Indies. In China one or more 

 species of Unio and Anodon are employed as pearl-makers, being domesticated in 

 ponds, and sundry foreign substances introduced within their valves, which the 

 occupant coats over with a thin film of 'pearl.' Among others, small metal images 

 of Buddha are introduced, and in the couise of some months are removed as 'idol 

 pearls,' which meet with a ready sale at moderate prices. There is nothing in the 

 nature of a 'pearl oyster' to render it more difficult to breed and rear than the 

 common edible oyster, but a trial can alone determine whether banks of pearl 

 oysters could be arlificially formed and worked to a pnifit. 



Perna. 



Hinge area wide, with numerous transverse elongated cartilage-pits. 



Malleus. 



Shell subequivalve, greatly elongated at the base. Beaks small, centi-al. Hinge 

 straight, edentulous, eared, with a long cartilage-pit under the beaks. The peculiar 

 elongation of the sheU is developed as the animal attains maturity, and is inconsider- 

 able in young shells. 



,, sp. 

 A .species of 'hammer oyster ' is sometimes met with, but has not been determined. 



