140 Correspondence—G. W. Lamplugh. 
and Clava are adequately explained without submergence, there is 
nothing improbable in a 400 foot submergence of the Central Plain 
of Ireland. Carvill Lewis adopted a 400 foot Irish submergence 
during the advance of the ice (Glac. Geol., p. 148). 
The chief difficulty in the marine origin of Irish boulder clay is 
its poverty in marine fossils; but the references quoted in my 
paper show that marine fossils are widely scattered in the Irish 
drifts. They are rare, and to explain their rarity I quoted from 
men so experienced in polar biology as Dr. Nansen and Mr. J. Murray 
to show that under some conditions life is absent from the Polar 
seas. Dr. Nansen’s statements that the floor of parts of the Arctic 
Sea are lifeless are not refuted by Gran having found the opposite 
in “samples taken later during the expedition”’. Similarly, in the 
Antarctic, Murray’s statement that the shore deposits at Cape 
Royds contain no vestige of life is not refuted by the occurrence of 
shells elsewhere and in beds which, owing to the scarcity of life 
along the shore, Hedley and Priestly reject as beaches and attribute 
to upheaval and upthrust. Even in the Swedish drifts, though 
shells are usually abundant, the clays are sometimes sterile over 
large areas. 
The marine origin of the Irish boulder clay is a subsidiary issue ; 
the object of my paper was to show by a description of the internal 
structure and field relations of representative Irish eskers, that 
the most important were not formed along intra-glacial rivers, but 
on the margin of the ice, where it ended in a sheet of water. Most 
of the eskers in fact are kames, not osar. I fully recognize that the 
evidence for the sheet of water being the sea is less clear than that 
as to the nature of the eskers. I only advance the view that it was 
the sea as being more probable than that it was a series of glacial 
lakes ; and there is nothing in Professor Kendall’s note to modify 
that opinion. I regret his adoption of a tone of discussion which 
seems to me as out of date as the view that all boulder clay may 
be simply explained as moraine profonde. 
J. W. GREGORY. 
THE AGE OF THE SHENLEY LIMESTONE. 
Sir,—lIt is fortunate that the Shenley echinoderms have received 
expert examimation, and our thanks are due to Professor H. L. 
Hawkins for his note on the subject in your February issue (p. 57). 
I will, however, ask for temporary suspension of judgment in respect 
to his deductions as to the age of the deposit. 
As the result of recent work, I shall be able to communicate to 
the Geological Society during the present session a paper containing 
much new evidence, both stratigraphical and paleontological, to 
prove that the limestone is in its proper position below the Gault, 
and that the Gault of the section belongs to the Lower and not, as 
supposed, to the Upper Gault. 
G. W. LAMPLUGH. 
St. ALBANS. 
February 10, 1921. 
