JOURNAL OF CONCHOLOGY. 355 



ant. The river Morda, a quick running stream rushing down 

 a rocky bed, was wonderfully well stocked with Ancylus 

 fluviatilis, a single stone the size of one's head often yielding a 

 dozen specimens. 



It was intended to visit Lake Bala, but this could not be 

 arranged. Most of the collecting was done whilst out driving, 

 and possibly more might have been done had more time been 

 at my disposal, but I can only hope that the little done may be 

 of some service and help forward the work of the society. 



"THE LOCALITY FOR LIMN^A INVOLUTA 

 Thompson." 

 By W. hill EVANS, M.D., M.C.S., &c., 

 In the number of the ' Journal of Conchology ' for July 

 Mr. Wilfrid Bendall contributes a notice as above. In the 

 ' Naturalist' for Nov. ist, 1864, I wrote a short account of an 

 ascent of Cromaglaun and the capture of a dozen of the Z. 

 involuta in the summer of that year. I was there in wet 

 weather ; while Mr. Bendall was there at the close of the very 

 dry summer of 1884, which circumstance will doubtless account 

 for our different ideas as to the extent of the Tarn. He gives 

 it as twenty feet across, when I saw it I feel sure that twenty 

 yards would be much nearer the mark. The hot weather may 

 also have had much to do with his want of success, as it is very 

 possible as he suggests that the mollusks might shelter in the 

 mud. Another cause may have operated — when I was there 

 my guide told me that I should have found a ' power more ' 

 had I been there a week earlier, but that a gentlemen from 

 London had a few days before swept the Tarn with a fine net 

 and secured a great number. 



This shell, although first described by Mr. Thompson, and 

 very properly associated with his name, was discovered by my 

 cousin, the late Dr. W. H. Harvey, for some time Professor of 

 Botany in the Royal Dublin Society, and the author of a well- 

 known work on British Sea Weeds — 'The Phycologia Britannica.' 



