MARINE MISCELLANEA. 247 



unfortunately proceeded so far that considerable difficulties are experienced in the 

 matter of obtaining a sufficient stock for the insurance of substantial results within 

 a reasonable period of time. Port Lincoln, on the South Australian coast, as a matter 

 of fact, represents the nearest and about the only spot where this most estimable 

 oyster still abounds in sufficient quantities to be available for importation and 

 laying down. 



For the resuscitation of the exhausted, and the maintenance of the existing, oyster 

 fisheries throughout Australia, there can be no doubt that methods of artificial 

 cultivation will have to be ultimately resorted to on a much more extensive scale, 

 and on more scientific principles, than have been hitherto pursued. Much has been 

 written upon this subject by the writer in his previously quoted volume and in Govern- 

 ment Reports to various of the Australian Colonies, and it will suffice here to refer 

 only to the illustrations of the apparatus introduced by him with marked success 

 at the Antipodes for the catchment of the free swimming oyster spat. This 

 apparatus, as shown in the top figure of Plate XLIV., consists merely of lengths 

 of board, the Australian " split pailing," having a brick attached at each end, and 

 a wire loop handle. The under surface of the board, immediately before being 

 placed in the water, is thinly coated with Portland cement. Three such "collectors," 

 with their crops of attached Rock oysters, which were laid down and taken up 

 by the writer in Moreton Bay, Queensland, after an immersion of about three 

 months, are portrayed in the lower photograph reproduced in the same Plate. This 

 description of spat collector was found to be equally efficacious when previously, 

 and for the first time, employed by the writer on the Tasmanian Government Reserves 

 for the artificial collection of the so-called "Mud" Oyster, Ostrcea edulis, which is 

 held to be only an Antipodeal variety of the British " native." 



A couple of hitherto unpublished photographs representing remarkable growths 

 of the ordinary Australian Rock Oyster, Ostrcea glomerata, and also of an 

 allied species, Ostrcea mordax, are reproduced in Plate XLIII. The growth of the 

 first-named species, occupying the lower half of the Plate, was photographed by the 

 writer in the Narrows, Keppel Bay, near Rockhampton, Queensland. It portrays 

 what may be denominated a virgin oyster reef as exposed to view at extreme low tide. 

 The representation of Ostrcea mordax in the upper of the two prints is a typical 

 illustration of the tendency of this species to form definite zones of growth around 

 restricted areas of the rocks to which it is attached. This zone of most luxuriant 

 development coincides, as a matter of fact, with half-tide mark ; scarcely an oyster 



