186 COLLIER AND STANDEN: 
tinetly, proving that the actual thickening has been deposited 
on the inner side of the whorls during the life of the animal. 
The climate of this part of Ireland is largely influenced by the 
Gulf Stream, and Dogs Bay facing west, with the sheltering 
mountain of Errisbeg immediately behind, is extremely mild and 
damp, and thus favourable to a lengthened life-period with very 
little hybernation—causes which would naturally conduce to a 
greater development of shell, both before and after normal 
maturity. The substance of the shells appears to have under- 
gone some chemical change during their long entombment, the 
usual calcareous material having been replaced by arragonite, 
which causes them to appear pellucid when wet, and renders 
them extremely hard. 
The marine shells of Dogs Bay are remarkable alike for 
abundance and variety, especially of the smaller species. The 
shore is almost wholly composed of one vast mass of nearly 
pure foraminifera, intermixed with small shells—principally 
Rissow, Odostomia, and Pleurotomide. We brought home a 
quantity of this drift, and with the kind assistance of Dr. G. 
W. Chaster, have examined a small portion, obtaining from 
it the greater part of the 112 species recorded during the 
excursion. The following are some of the more notable 
records :—Lima hians, L. subauriculata, Arca tetragona, Lepton 
nitidum, L. Clarkia, L. Sykesi, Montacuta bidentata, M. ferru- 
ginosa, Lasea rubra, Tellina donacina, Solen vagina, Tectura 
virginea, Trochus helicinus, Rissoa fulgida, R. soluta, Skenea plan- 
orbis, Homalogyra atomus, H. rota, Caecum glabrum, Scatlarta 
Trevelyana, S. clathratula, Odostomia turrita, O. diaphana, O. 
lactea, O. nitidtssima, Lanthina rotundata, Eulima distorta, 
Lamellaria perspicua, Cerithium perversum, Trophon truncatus, 
Defrancia linearis, D. purpurea, Pleurotoma costata, Cylichna 
cylindracea, Philine punctata, Aplysia punctala, Spirialis retrover- 
sus, and many other common species. Besides the mature shells 
a vast number of embryonic specimens are present, usually in 
beautiful condition. Caecum glabrum with spiral attached is 
J.C., viit., April 1896. 
