20 Mr. W. Thompson's Catalogue of the Land and 



London, to which it might much more readily have been in- 

 troduced along with exotic plants. In a garden at Bandon, too, a 

 Testacellus has been procured by Mr. G. J. Allman. The circum- 

 stance of this species, indigenous to France and to the island of 

 Guernsey, being found only in the south of England and Ireland, 

 seems to me strongly in favour of its being equally indigenous to 

 these countries. Mr. Ball, in reply to some questions, observes, " I 

 first became aware of this Testacellus preying on worms by putting 

 some of them in spirits, when they disgorged more of these animals 

 than I thought they could possibly have contained ; each worm was 

 cut (but not divided) at regular intervals. 1 afterwards caught them 

 in the act of swallowing worms four and five times their own length. 

 Some of these Testacelli, which I brought to Dublin and put in my 

 fern house, produced young there." 



Testacellus Maugel is noticed by Dr. Turton (Manual, p. 28.) as 

 found "in Ireland," but I have been unable to give any information 

 respecting it, and these two words seem to me insufficient to esta- 

 blish it either as an introduced species or otherwise. 



4. Helix. 



1. Helix aspersa, Mull. Gray, Man. p. 128. pi. 4. f. 35 ; Drap. p. 89. 

 pi. 5. f. 22. ; Mont. p. 407. 



Although distributed over the four quarters of the island, this 

 Helix is less generally met with than several other common species. 

 In a well-cultivated and moderately wooded district near Belfast, 

 stretching along the base of the mountains where chalk chiefly pre- 

 vails, presenting different soils, especially clay and alluvium, and 

 rising to an elevation of 500 feet above the sea, it is never found. 

 Mr. Edward Waller, who has successfully investigated the Mollusca 

 about Annahoe, county Tyrone, states that the H. aspersa is un- 

 known there. It seems partial to the vicinity of the sea ; so much so, 

 that about Ballantrae in Ayrshire, Scotland, I have remarked num- 

 bers of them on rocks, subjected to the spray of the waves, which had 

 bleached the portion of the shell thus exposed as white as it usually 

 becomes in the progress of decay, although the animal inhabitants 

 were all in the highest vigour. In the crannies of the ruined castles, 

 which, like Dunluce, are based upon the summits of some of the high- 

 est cliffs washed by the sea in the north of Ireland, the-H. aspersa is 

 abundant. 



In one instance which may be mentioned, differences of rocks, 

 soil, or shelter will not explain the absence of this species from par- 

 ticular localities. During a forenoon's walk on the marine sand- 

 hills of Portrush and Macgilligan (county of Londonderry), which 

 are only a few miles apart, and present in every respect precisely 

 the same appearance, I found the H. aspersa abundant at the for- 

 mer, but at the latter wanting, and here the sand-hills are much 

 more extensive than at Portrush. At the nearest sand-hills, again, 

 on the coast to the east of the latter, and only a few miles distant, 

 I did not during a short visit find the H. aspersa ; and here Helix 

 virgata, which is not found at the other two localities, appeared, and 



