23 38 Proceedings of the Royal Irish Academy. 



like Limnaea auricularia- var. acuta, Planorbis crista, and P. glaber, a number 

 of species are found which are unknown in other parts of the west coast. 

 These latter are some of the more widely-ranging members of the central 

 fauna, and include Limnaea stagnalis, Physa forvtinalis, Bithynia tentaculata, 

 and Sphacrium corneum. Immediately north of the entrance to Killary 

 Harbour is a rough uncultivated area of heavily glaciated rocky knolls 

 known as Dooaghtry. This, on the landward side, is in sheltered places 

 covered with patches of dense scrub, while towards the west it is 

 deeply covered with blown-sand. It contains three shallow lakes and a fair 

 extent of marshy ground. Dooaghtry is perhaps the richest sanctuary for 

 mollusca on the west coast, and provides shelter for no less than sixty-three 

 species. Besides Zonitoides nitidus, Z. cxcavatus, Acanthinida aculeata} 

 A. lamellata, Hygromia fusca, Balea -perversa, Pupa anglica, Vertigo anti- 

 vertigo, V. sitbstriata, V. pygmaea, Acicida lineata, Limnaea auricularia, 

 and Planorhis glaber, we find here two species — Vertigo angustior and 

 Svxcinea oblonga — which are otherwise unknown in West Mayo. Both these 

 shells are common, but whereas V. angustior is confined to the shore of 

 Dooaghtry Lough, the latter is widespread and swarms over several miles 

 of country, wherever damp marshy land is to be found. A note on the 

 habitat of this Vertigo may be interesting, since it is similar in every 

 respect to that in which it occurs at Dog's Bay in West Galway. It lives 

 on the sides of stones sunk in more or less wet ground, and is particularly 

 common on clumps of the moss — Hypnum velutinum — which grow on and 

 around the stones. Throughout the coastal portions of this district of 

 Louisburgh Helicclla itala is abundant and H. intersccta (the large western 

 form) occurs on the sand near the town of this name. Thus the inexplicable 

 absence of H. barbara is more pronounced. The effect of exposure near the 

 coast is shown to a great extent on PP. itala. On the flat wind-swept swards, 

 where the turf is still unbroken, thousands of this shell, of a size no bigger 

 than an ordinary Hygromia hispida, may be found sheltering under a 

 vegetation which has all the appearance of a well-kept lawn. In the 

 hollows of the dunes, in some cases no more than one hundred yards from 

 where the dwarf form lives, moderate-sized specimens occur, which bear 

 little or no resemblance in colour, texture, or shape to their puny neighbours. 

 Similar forms appear to occur on the west coast of France : from these several 

 supposed species have been described, which we in this country probably 

 include in our Hclicella itala. (Plate II, figs. 44 & 45.) 



1 A single specimen of the spineless form, var. sublaevis West., occurred amongst scrub at 

 Dooaghtry. This appears to he a very rare variety, as only a few previous instances of its occurrence 

 in Irelanil are recorded. 



