334 Quarterly Journal of Conclwlogy. 



No doubt Mr. Rimmer's surmise is correct as to the intro- 

 duction oi pisana to Vazon Bay, but it must have been soon after 

 his visit, as many of the shells would complete their growth in the 

 season in which I saw them, and according to my own observa- 

 tions, it is usually in the third year of their growth that our larger 

 mollusks finish their shells. 



It would be well if the person who introduces an animal or 

 plant into a new locality would record the fact in one of our 

 natural history periodicals, as it would greatly help those of us 

 who wish to arrive at a knowledge of their natural distribution. 



Mr. Rimmer's explanation of the probable cause of the 

 congregation of adult shells is doubtless right. 



I do not think aspect would prevent the successful establish- 

 ment of H. pisana on our coast, if the parents were introduced 

 in early summer before breeding commenced. Its Irish habitat is 

 an Eastern one. 



H. fomatia and H. cantiana find no difticulty in accommo- 

 dating themselves to Yorkshire. 



It would be interesting to ascertain if it could be successfully 

 introduced into some inland station in this country. 



The discovery of Dr. Gwyn Jeffreys' colony at Swansea is 

 noteworthy. In speaking of it Mr. Rimmer says the variety alba 

 seemed to be the most plentiful, does he not mean the creamy 

 white variety? not alba^ which is, as I pointed out, a snowy opaque 

 white with (Mr. Shuttleworth says sometimes without) translucent 

 markings. 

 Dec, 1877. 



