185 



NOTES AND EXHIBITS. 



Mr. Hedley showed samples of young oysters from Vaucluse 

 Bay destroyed l)y the operations of a boring mollusc, Ricinula 

 marginatra, Blainv., together with examples of the latter; and 

 he communicated the following Note : — 



" Wherever oysters ai'e used, species of carnivorous gasteropods 

 — whelks, whelk-tingles, or borers — have been seen to prey upon 

 them. On the coasts of England and France an especial pest is 

 Murex erinaceus, the target for whose piercing radula is the 

 thinnest part of the half-grown shell. Fischer has described 

 (Journ. de Conch, xiii. 1865, pp. 1-8) the havoc wrought by this 

 species in the " pares " at Arcacahon. The experiments and 

 observations of Lieut. Winslow, detailed in the Eeport of the 

 United States Coast and Geodetic Survey for 1881, p. 70, prove 

 the damage effected by Urosaljnnx cinereus, in Long Island Sound. 

 Mr. Saville Kent describes and illustrates the harm done in More- 

 ton Bay to young oyster brood by Urosalpinx paivce in his Report 

 on the Oysters and Oyster Fisheries of Queensland, Brisbane, 

 1881, p. 10, pi. I. ff. 1, 10, 11. 



"A few days ago (22nd April, 1894) my attention was directed 

 by J. Hill, Esq., to a mollusc not hitherto accused, at least in 

 books, of evildoing. A heavy fall of spat had coated thickly with 

 young oysters the rocks, between tide marks, in Vaucluse Bay. 

 Most of these had already died and lost their upper valves. An 

 examination showed Ricinula marginatra, Blainville, to exist in 

 such abundance that from a square foot one of our party gathered 

 a handful. Further search betrayed several specimens settled on 

 doomed oysters, whose upper valves were firmly grasped by the 

 aggressors' feet. On plucking off the Ricinula I repeatedly found 

 a hole partly or completely drilled through the oyster shell. All 

 the victims were young oysters the size of a penny. Specimens 

 of destroyed and destroyer, seized in the act of boring, are now 

 submitted for inspection." 

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