445 
to exist in the Arctic seas, and two, Natica glaucinoides, a crag fossil, 
and Astarte propinqua, are believed to be extinct. 
Post-Tertiary Deposits—The author prefixes to his account of 
these beds a notice of the older formations in that part of Ayrshire. 
The prevailing rock is red sandstone, which, at almost every. point 
on the coast, has been worn, by the former action of the sea, into 
cliffs, which indicate a change of level of about forty feet. The ter- 
race at the base of the cliff, Mr. Landsborough states, ray be con- 
sidered a marine raised beach, and the shells contained im it are, with 
two exceptions, one of which is doubtful, of existing species. 
At Ardrossan, a deposit twenty feet above the level of the sea, 
and at Kelly, the soil which covers the base of the inland cliff to the 
height of thirty feet, are full of common marine shells. Similar beds 
are stated to occur in the islands of Arran, Cumbra, and Inch Mar- 
nock. In the parish of Stevenston, immediately under the vegetable © 
soil, is a bed of shingle, in which forty-seven species of shells com- 
mon on the adjacent shores have been found. It rests upon shale. 
perforated in many places by the Pholas crispata, of which the shell, 
in a very friable state, is generally found within the cavity. 
At Largs the shore rises to the height of twenty feet above high 
water. Under a bed of loam, from five to ten feet above the sea- 
level, is a sandy stratum one foot thick, from which Mr. Lands- 
borough has obtained specimens of Millepora polymorpha, and seventy 
species of marine shells, the whole of which are well-known inhabi- 
tants of the British seas, except two species of Rissoa, one of which 
had been previously found only in the crag, and the other is referred 
with doubts to the Rissoa Harveyii of Mr. Forbes. 
Respecting the age of this deposit, Mr. Landsborough states, that 
160 species having been found in it by Mr. Smith and other geolo- 
gists, it would be rash to infer from the above two exceptions, ‘‘ that 
there is a difference in the faunas of the existing period of sea-level 
and of that which preceded it; but he thinks it is not improbable 
that some change may have taken place during the very long period 
in which the inland cliff was formed by the slow wasting of the sea ; 
and he adds, the position of the bed at Largs, being ten feet under 
the surface, indicates a considerable antiquity, although its age must 
be much newer than that of the Phocene strata, in which there is a 
decided proportion of extinct Testacea. 
Lists of the shells found by the author at each locality accompany 
the paper. ; 
2. A letter from Capt. Alexander, F.G.S., ‘‘On the Annual De- 
* struction of Land at Easton Bavent Cliff, near Southwold.” 
From careful observations, made during the last five years, Capt. 
Alexander is of opinion, that the local statements, of 350 yards in 
breadth having been destroyed at Easton Cliff in about thirty-five 
years, are not much overrated, as, during that period,-a nearly square 
field, containing twelve and a half acres, has been entirely removed 
by the sea, and as only three acres remain of another which con- 
