1865.] LAKKESTER CEAG MAMMALIA. 221 



with, a cross fault to the N.W., which has manifestly helped to 

 protect certain patches of Boulder-clay, and expose others, giving 

 an unequal activity and various directions to the denudation which 

 during the rise of the land took place to so large an extent over 

 the whole district. The undulations in the Boulder-clay are often 

 exceedingly rapid and deep, within very limited areas. 



At the same time there is evidence that the land was uplifted by 

 a force acting upon different points with different degrees of in- 

 tensity. A series of sheU-beds may be traced from the half-tide 

 mark opposite Dumbarton, by Dalmuir, Jordan Hill, to Airdrie, occu- 

 pying levels which gradually rise until at Chappel Hall they reach 

 the height of 526 feet. 



Becollecting, therefore, that the shell-bed in question is on the 

 slope of a ridge of Boulder-clay, and that the denuding and elevating 

 forces were both unequal, it is evident in what way the old Boulder- 

 clay may have been carried over the shell-bed, its stones in the pro- 

 cess losing their striations and much of their smooth polish, at a 

 period long subsequent to its own original deposition. 



As regards the whole case, it is submitted that while there is no 

 evidence whatever that the Chappel Hall fossils were in the Boulder- 

 clay, in any sense which would make that clay a marine formation, 

 it is also not proved that they occupy any position different from 

 that held by the common shell-beds of the Glacial epoch in the west 

 of Scotland. 



February 8, 1865. 



Captain "William Arbuthnot, 25 Hyde Park Gardens, "W. ; Robert 

 Bell, Esq., Professor of Geology in Queen's College, Canada West; 

 William Henry Leighton, Esq., 2 Merton Place, Chiswick; and 

 Viscount Milton, E.R.G.S., of Wentworth Park, and 4 Grosvenor 

 Square, W., were elected Fellows. 



The following communications were read : — 



1. On the Sources of the Mammalian Fossils of the Red Crag, and 

 on the Discovery of a New Mammal in that Deposit, allied to the 

 Walrus. By E. Ray Lankester, Esq. 



{Communicated by Prof. T. H. Huxley, F.E.S., F.G.S.] 



(Plates X. and XL) 



I. The Sources of the Mammalian Fossils op the Red Crag. 



The very remarkable deposit extending over a small area on the 

 east coast of England, and known as the Red Crag of Suffolk, from 

 time to time furnishes fresh remains of a very various Mammalian 

 fauna. Indeed, so diverse are the forms which occur in this small 

 deposit (whose total number of Mammalian fossils does not exceed 



