OYSTEK-CULTUEE IN AUSTRALASIA. 555 



tide was well down. In further corroboration of its specific 

 distinctness it was found, on examination with the microscope, 

 that these diminutive oysters were laden with mature ova. 

 Some idea of the minuteness of this oyster will be gained by a 

 reference to the photographs of this and other species of 

 Australian oysters prepared by me for the illustration of this 

 paper. In the one representative of this pigmy type it may be 

 observed that as many as fifty or more mature oysters were in 

 several instances located, without crowding, upon a single leaf 

 of the Aviccnnia, wliich is less than 3in. long. Young indi- 

 viduals scarcely exceeding a pin's point in dimensions were 

 also scattered among the mature examples, or, as commonly 

 occurs with ordinary commercial oysters, growing upon the 

 living or defunct shells of their parents. More than a year ago 

 I presented examples of this minute and apparently new species 

 of oyster to an eminent Australian conchologist for the purpose 

 of careful comparison with, and relegation to an appropriate 

 place among, the numerous members of its genus. No results 

 having, however, so far arisen from the steps taken to secure 

 it a recognised position among its congeners, I take this 

 opportunity of naming it Ostrea ordensis, with reference 

 to its habitat, and append to this paper a brief technical 

 diagnosis that will facilitate its future identification if ob- 

 tained from other localities. 



Oyster-cultivation. 

 In dealing with the important subject of oyster-cultivation, 

 I propose to take the several oyster-producing colonies of 

 Australia in rotation, and to indicate briefly the nature and 

 results of the operations that have been conducted therein. 

 The island of Tasmania being the colony with which I was 

 first officially associated, and where for a period of nearly 

 five years the oyster-fisheries engaged my special attention, I 

 may appropriately select it as the subject of my first remarks. 

 The oyster of Tasmania, as previously indicated, co-responds 

 so closely with the type Ostrea edulis, produced and cultivated 

 in British waters, that it is held by most biologists to be 

 identical with it. This oyster was so abundant in former years 

 in Tasmanian waters that, as vouched for in the report of a 

 Eoyal Commission of Fisheries held in the year 1882, about 

 twenty years previously a quantity representing at current 

 prices a retail value of no less than £90,000 was exported in a 

 singla year to Victoria and New South Wales. Oysters, in 

 fact, were so plentiful at that time that it was a common 

 practice to burn them wholesale for the purpose of making 

 lime. This woful waste of Nature's bounties soon reaped its 

 merited reward. The oyster-grounds became so depleted by 

 the unrestricted drain upon their resources that in a few years 



