2 The Irish Naturalist. January, 
made, and with those collected at Belderrig, submitted 
to Canon Grainger, m.r.i.a., who named the following :— 
Tellina calcarea Cyprina islandica 
Saxicava rugosa Leda pernula 
Leda abyssicola ? Buccinum undatum 
Mya truncata Mytilus modiolus 
Fusus antiquus Balanus 
Natica (borings) 
Overlying the Boulder-clay occurred sands and gravels, 
which at Glenulra and Glenglassera attained a considerable 
development, and at these places contained shell-fragments. 
The natural history survey of Clare Island during the 
past few years raised many questions of geological interest, 
and one of the most important was the evidence for any 
considerable change of climate during the Glacial Epoch. 
The occurrence in the Boulder-clay of the shells of marine 
mollusca, the distribution of which is to-day either arctic or 
northerly, is considered as tending to prove that at that time 
the climate was much more severe than at the present day. 
Among the species of mollusca obtained from the Boulder 
cla}^ of Clare Island not one occurred which is not still com- 
mon and widely distributed around the British and Irish 
coasts. A further search of Clew Bay yielded no faunistic re- 
sults, and it was then decided that an examination of the 
north Mayo deposits should be undertaken, as in Canon 
Grainger's list at least two of the mollusca — Tellina calcarea 
and Leda pernula— were of those northerly types, which are 
not present in the British seas of to-day, and it was hoped 
that a further search might add to the number. The 
conditions under which the unbroken valves of Tellina 
calcarea occurred was also considered as a matter to be 
looked into, as such large, flat, fragile shells are very seldom 
found imbroken in true Boulder-clay. 
With these objects in view two visits were paid to north 
Mayo during the past year — one in August, when days 
of unceasing rain were a great advantage for the collection 
of shell-fragments — the second in October, when a drought 
of three weeks had emptied the streams in many cases to 
dryness, enabling one to move about freely and inspect the 
sections. The coast from Lackan Bay to Portacloy, a 
