J. §. GARDNER ON BRITISH CRETACEOUS NUCULID. 145 
Discussion. 
Dr. Gwyn Jerrreys doubted the necessity of forming a separate 
family of Nuculide. He included them in the Arcide. He had 
examined the Gault collection of Mr. Gardner, which appeared to 
contain ten times as many species as had already been described 
from that formation. He considered that the Gault Nuculide 
lived at a depth of from 50 to 100 fathoms, and this view was 
confirmed by the nature of the materials forming the Gault clay. 
Prof. T. Rupert Jonus said that in many parts the Gault swarms 
with Microzoa, and these seemed to confirm Dr. Gwyn Jeffreys’s 
view that the Gault was formed at a depth of about 100 fathoms. 
The AvrHor thought that the limited area covered by the true Gault 
clays and the presence of coniferous wood and fruit pointed to the 
conclusion that the Gault was an estuarine deposit. ‘He believed 
the evidence indicated that the Gault was deposited in a gradually 
deepening sea. 
Q.J.G.8. No. 157. L 
