270 The Irish Naturalist. 



considerably since Mr. Darbistire's visit, and no *' black band " answer- 

 ing to his description could be found. But, in several places where the 

 wind had cut a clean section through the sand-dunes, the old land 

 surface was exposed and showed plainly as an earthy layer about a foot 

 deep, quite distinguishable from the blown sands above and below, and 

 this was full of land shells in good preservation, all the species men- 

 tioned by Mr. Darbishire being obtained, together with several additional 

 ones. The H. 7iemoralis found in this earthy layer are of ordinary char- 

 acter, and comparatively recent, most of them still retaining traces of 

 colour. The large and massive specimens, which undoubtedly belong 

 to an earlier epoch, all occur in the stratum below, which is from three 

 to four feet deep, and composed of clean sand, foraminifera, and finely 

 comminuted shells. As the shells from these separate layers are 

 weather out, they are blown about the sandhills and accumulate in 

 the hollows, where they lie by hundreds intermingled together, but 

 specimens belonging to the two epochs may be determined at a 

 glance by their comparative size, and by the nature of the material with 

 which they are filled. The older shells are not only remarkable for 

 weight and solidity, but also for their dimensions. Some specimens 

 measure 28 mills, in breadth, by 18 mills, in height, but the elevation of 

 spire varies considerably, some examples being very depressed. Some 

 specimens are umbilicated, others have a thick, heavy, curiously constric- 

 ted lip, folding inwards near the suture, and forming a tooth-like pro- 

 tuberance. Variously banded forms occur, but they are mostly bleached 

 pure white, and as a rule are very perfect, except that in some cases a 

 narrow triangular portion of the lip near the suture is broken out, but this 

 is probably owing to the action of frost. The substance of these massive 

 shells is not calcareous as in recent examples, but more of the nature 

 of arragonite, and the deposition of the material in layers is well shown 

 by making a section of the shell. The following is a full list of the species 

 found in the deposit: — Vitruia pelhccida, Hyalinia cellaria, H. nitidida, H. 

 pura, H. crystallina, H. ftdva. Helix aciilcata, H. neinoralis, II. riifescens, H. 

 hispida, H. concinna^ H. virgata, H. capcrata, H. ericetorum, H. pygmaa, H. 

 aspersa, H. pukhella, II aaita, Pupa inuscortim, Vertigo angnstior, V. pygmcea, 

 V. substriata, Clausilia bidentata, Cochlicopa lubrica, Carychiiim mininnu7i, Acme 

 lineata. Careful search in the immediate vicinity for living examples of 

 above only yielded H. aspersa, H. acuta, H. ericetorum, and P. vtuscorum. 

 Some specimens of H. nemoralis of ordinary character were, howeven 

 found living on the road to Roundstone. 



