128 EDIBLE OYSTERS EOUND ON THE AUSTEALIAN COAST, 



that siicli is the case, that oysters are gathered off our rocky 

 shores in large numbers and are laid down in positions in which 

 it is thought a bed of oysters would thrive similarly to the beds 

 which are found of this species, and that they will there grow 

 spawn and reproduce Drift Oysters ; this is a great error, and a 

 want of knowledge of the true habits of this species and our 

 common Rock Oyster {Odrea glomerata), has led to disappoint- 

 ment and loss in attempts which have been made to cultivate 

 oysters as a commercial investment. 



The spat from our Eock Oyster will never produce this species, 

 and if this species is placed in a position where it is uncovered by 

 every receding tide it wastes and dies, but if kept well immersed 

 it will thrive, fatten and reproduce itself, especially if it is placed 

 in a position where there is a good current of water. Again our 

 Rock Oyster has been placed in a similar position to the natural 

 beds of the Drift Oyster {Ostrea sultrigona) but always with 

 disappointment ; when our Rock Oysters are placed in such a 

 position they will not thrive and fatten, and in fact will not live 

 very long, but will live longer than if the Drift Oyster is placed 

 in the natural position of the Rock Oj^ster, uncovered night and 

 morning by the fall of the tide. This species is considerably 

 preyed upon by other mollusks. 



3. OSTREA GLOMERATA, Goillcl. 



The common Rock Oyster of this harbour. Mr. Angas has, 

 as I have already pointed out erroneously called this species in 

 his list of Port Jackson Shells, Ostrea mordax of Gould. The 

 Rev. J. E. Tenison- Woods in his '' Census of the Marine Shells of 

 Tasmania," tells us of the existence of a Rock Oyster similar to 

 the Rock Oyster of New South Wales, which he also calls Ostrea 

 mordax of Gould ; and Mr. Angas in his paper on the '' Molluscan 

 Fauna of South Australia " speaks of the common Rock Oyster 

 of that locality as Ostrea cucullata, Born, and states that it extends 

 from King George's Sound to New South Wales, (this is also 



