408 THE ZOOLOGIST. 



recorded Crepidula as among the indigenous genera of British 

 shells. Having located America as the original habitat of these 

 " Slipper Limpets," the question arises, How and when were 

 they brought alive to Britain ? 



A case in point may be cited, namely, that of our Common 

 Periwinkle {Littorina littorea). This stranger to the United 

 States fauna is supposed to have got there in 1868* from having 

 been shot out alive among the ballast of the shipping. Since 

 then it has become naturalized and spread abundantly. But 

 the close adherence of the living " Slipper Limpets" to Oysters 

 bespeaks that they undoubtedly were the means of conveyance. 

 Proof of this will be given further on. Here sufficient for our 

 purpose to refer the reader to paragraphs on the introduction 

 of American and Dutch Oysters foj- laying in the * Fish Trade 

 Gazette' of Oct. 10th, 1891 (p. 11), where it is stated this was 

 some fifteen or twenty years previously, otherwise between 

 1870-1876. 



Among data concerning the presence of the "Slipper Lim- 

 pet" on the coast of England facing the North Sea we give the 

 following : — 



York and Lincoln. — Arthur Smith,! of Great Grimsby, has 

 recorded his having found the shells of Crepidula fornicata near 

 Cleethorpes in November, 1887, and he mentions that he learned 

 they were brought thither with consignments of [barrelled] 

 American Oysters. Furthermore, B. Sturges Doddt makes the 

 rather important statement that in February, 1887, two barrels 

 of Oysters were received from a firm from New Basford [query : 

 New Bedford, U.S. — J. M.], in which were several dozen of 

 Crepidula, Anomia, and Barhatia. He reasons therefrom that, 

 seeing the Oysters imported to Britain are relaid at Cleethorpes 

 and elsewhere in the Humber-mouth neighbourhood, they {Crepi- 

 dula fornicata) ultimately may hereafter become acclimatized. 

 H. Wallis Kew§ also alludes to their presence on the Lincoln- 

 shire coast. Quite lately, on inquiry of Herbert Donnison, 

 Inspector of Eastern Sea Fisheries District, he tells us they 



* Winslow, Cat. Econom. Mollusca of U.S.A. 



f ' Yorkshire Naturalist,' 1888, p. 27. 



I Proc. Malacological Soc. vol. 1. pt. ii. p. 31 (March, 1894). 



§ 'Yorkshire Naturalist,' 1889, p. 358. 



