36 



DIVISION 46, e. 



EDIBLE MOLLUSCA. 



Oysters. 



(Ostrea glomerata, O. virescens, O. subtrigonia, So7a.^ 

 O. mordax, G/i/., O. edulis, var. purpurea, Hanley) 



A large collection of Oysters, in numerous varieties, and 

 from beds in different localities. Most of these beds are 

 natural beds, very few of them formed by artificial layings ; 

 all are under lease, and more or less under cultivation. 



The Rock-Oysters, although usually known under several 

 different names, are now by most conchologists admitted to 

 be only localised varieties of one and the same species, 

 Ostrea glomerata. If we accept this view, then we have only 

 two species which are used as articles of food — O. glomerata, 

 in its many varieties, and O. edulis, L., O. piirptirea being 

 only a variety of the latter, which is identical with the small 

 form known as the " Native " in the London markets. 



Ostrea sp. (No. 69), from Coffin's Bay in South Australia, 

 is another variety of the same species found in the Adelaide 

 market, and frequently producing irregularly formed pearls 

 of larre size but of no commercial value. 



o 



Ostrea virescens is a rare species, only occasionally found 

 at very low tides on some of the numerous islands in Port 

 Jackson. Other species {O. crista-galli and O. imbricata) 

 were obtained by Mr. A. Morton at Port Denison, Queens- 

 land ; and the ^' Hammer-head Oyster " {Malleus albus, 

 Lam.), &c., are found on our coasts, but do not find their 

 way into the market as articles of food. 



The following collection, from 70 different beds and loca- 

 lities, is exhibited to show the numerous forms which our 

 Ostrea glomerata assumes in various places, and the great 



