672 Proceed in rji of the Royal Irkh Academy. 



XLII. — Atjthenticated Materials towaeds a Land and Feesh- 

 WATEE MoLLUscAN Fauna OF Ikelakd. By JoHN W. Tatlor and 

 W. Denison Eoebuce:, F.L.S. [Communicated by W. F. de 

 YisKEs Kane, M.R.I. A.] 



[Read, June 28, 1886.] 



During the past year or two we have been favoured by several friends 

 ■with interesting consignments of Mollusca from various parts of Ire- 

 land, and in particular we are indebted to our friend Mr. W. F. de 

 Yismes Kane, whose kindness in collecting and sending to us specimens 

 of Irish slugs from various counties has been of much service to us in 

 our work of monographing the British Land and Freshwater Mollusca 

 — by indicating that the Irish Fauna has in this department of Natural 

 History a tendency to the development of a character somewhat diverse 

 from that of Britain, or perhaps, to speak more correctly, from that of 

 England. This being so, it is desirable that the Molluscan Fauna of 

 Ireland should be worked out in more detail than has hitherto been 

 done, and that we — having in course of preparation a new monograph 

 of the British Land and Freshwater Mollusca based upon an extensive 

 and elaborate plan — should have the opportunity of seeing specimens 

 fi'om every county and district of the island. It seemed to us, there- 

 fore, that an account of what we know up to the present moment fi'om 

 actual inspection of specimens would be of some service, both as a 

 contribution to a new fauna of Ireland, and as- an indication to Irish 

 I^aturalists of the nature and character of the assistance we should 

 like to receive at their hands. We may say, moreover, that the plan 

 of our proposed work, being an exhaustive and detailed one, renders it 

 impossible for us to see too many specimens ; and as the detailed study 

 of minute variation enters as a principal factor, it is desirable that we 

 should have extensive consignments of the commonest and most 

 prevalentspecies, in addition to the rare and special ones, as being more 

 likely to furnish us with suitable and adequate material for study. 



We are not yet in a position to institute a comparison with the 

 works of Thompson, Clarke, and other famous Irish jSTaturalists, further 

 than to say that we have had submitted to us examples of nearly all 

 the species which appear in their lists, and that the additions we have 

 to make are but three in number, all slugs. The first is Testacella 

 maugei, the second is Limax cinereo-niger, and the third is Arion 

 suhfuscus. The last of these is one which we have recently satisfied 

 ourselves, from the anatomical observations of our friend Mr. Charles 

 Ashford of Christchurch, should be added to the British list. It is as 

 common in the British Isles as on the continent, and has hitherto been 

 confounded by British ^Naturalists with the other species of Arion. 

 Limax cinereo-niger is a fine and conspicuous species, very distinct 



