OYSTERS AND OYSTER FISHERIES OF QUEENSLAND. 245 



in Fig. 7 of Chromo plate XIV., illustrative of the oyster series. The larger individual shells 

 of this tropical species not unfrequently measure as much as six or seven inches in their 

 longest diameter Their edges, in contradistinction to those of the preceding species, are 

 usually perfectly even, or only slightly indented. A notable feature of this oyster is the very 

 hard vitreous texture of its shell. Its colour externally is usually' a light slate-grey, while 

 internall}' it is pure white with a conspicuous broad black marginal border. In association with 

 this last-named feature it has received the name of the Black-edged oyster, Ostrea iiigro-margiiiata. 

 While by no means an unpalatable oyster in the raw condition, like the preceding species, it 

 finds greater favour stewed or scalloped. The Black-edged oyster flourishes side by side with 

 the form next to be noticed [Ostira inorr/ax) throughout the reefs and islands of the Great Barrier 

 .system, and it is particularly large and abundant on the rocky foreshores of Adolphus and other 

 islands in the vicinit\' of the Albany Pass, Torres Strait, whence it is extensively obtained as a 

 seasonable delicacy for the settlement at Somerset. The hardness of the shells of this species, and 

 the difficulty of detaching them from the rocks without fracture, even with the aid of hammer and 

 cold chisel, have hitherto proved somewhat of a bar to its utilisation for commercial purposes in 

 the ordinary manner. Within the past two years, however, this black-edged oyster has been 

 discovered in large quantities in the vicinity of the Flinders Islands, immediately north of Cape 

 Melville, and from this locality it has been systematically collected and distributed to Thursday 

 Island, and to the populous districts of Normanton and Cro^'don, accessible from the Gulf of 

 Carpentaria. By laying the oysters for a while, in bulk, on suitable foreshore areas, they recover 

 from any injuries received in the process of detachment ; if fatally wounded, their bodies speedily 

 decompose and are washed out from the shells, leaving all the sound oysters in condition prime 

 for transport. The foundation of a new industry has in consequence been laid in association 

 with the commercial utilisation of this oyster, that is capable of indefinite extension. A concep- 

 tion of the possibilities associated with the cultivation of this species may be arrived at from the 

 circumstance that the first consignments transported to the inland mining centre of Croydon 

 readily obtained a retail price of 2s. 6d. per dozen, as compared with 6d. per dozen, the price 

 usually paid for Ostrea glontcrata in the Brisbane market. In testimony to the substantial dimen- 

 sions which this oyster attains, it may be mentioned that the hollow shell, illustrated by Chromo 

 plate XIV., Fig. 7, was found to possess a holding capacity of four fluid ounces, or the equivalent 

 in weight of one-quarter of a pound of "oyster meat." 



The third species of edible oyster, other than the ordinary commercial variety indigenous 

 to Queensland, is the so-called Ostrea niordax, of Gould. Its area of distribution is a much 

 wider one than that of the two preceding types, as it is found abundantly throughout the whole 

 length of the Queensland coast-line, from the Gulf of Carpentaria and Cape York in the extreme 

 north, to the New South Wales boundary at the Tweed Heads. It has also been recorded 

 from Fiji, Samoa, and other island groups in the Pacific Ocean. 



