THE ZOOLOGIST 



No. 845. — November 15th. 1911. 



" SLIPPEK LIMPET " OE " BOAT SHELL " {CREPI- 

 DULA FORNIGATA): ITS INTRODUCTION AND 

 INFLUENCE ON KENT AND ESSEX OYSTEE- 

 BEDS. 



By James Murie, M.D., LL.D., F.L.S. 



(Member of Kent and Essex Sea Fisheries Committee). 

 (Plates VI. & VII.) 



Preliminary Eemarks. 



As may be inferred from the title, the purport of this com- 

 munication has reference to an American mollusc introduced 

 into British waters, and whose presence is suspected to have a 

 deleterious effect on the Oysters. This, be it observed, is the 

 current opinion of many of the oystermen, though another 

 section of them express doubts concerning its hurtful nature. 

 The subject thus assumes an importance in so far as Oyster 

 Fisheries are concerned, and these, it will be admitted, are 

 historically and up to the present day a distinguishing feature 

 of Kentish and Essex marine industries. 



Before proceeding to deal with the American intruders, it 

 may be useful to take a limited survey of what more pro- 

 nouncedly are regarded as the enemies of our Native Oysters. 



Among our oystermen and those engaged in the industry 

 the so-called "vermin," looked upon by them with decided 

 aversion, are the Five-fingers, the Mussels, and the Tingle or 

 Dog-Whelk. 



(a). First and decidedly foremost of these is the Starfish 

 {Asterias ruhens), which notoriously is well known to be a deter- 

 Zool. Mh ser. vol. XV., November, 1911. 2 i 



