22 



t 



be due to rainwash, but finds some difficulties in the way of 

 this explanation. Amongst these he adduces two instances of 

 lateral thrust, causing a reduplication of the coprolite bed, one 

 of which he accounts for by supposing the upper bed to be a 

 travelled mass in the trail. Finally from these and other con- 

 siderations he concludes that the irregularities in the surface 

 of the Gault near its outcrop are probably due to the action 

 of land ice, and that the gravelly ^' trail" above is the remnant 

 of the moraine profonde which was pushed forward beneath it. 



1872. "An Outline of the Geology of the Upper Tertiaries 

 of East Anglia," by Messrs S. V. Wood Junr. and F. W. Harmer, 

 appeared as a preface to the volume issued as a supplement 

 to Mr S. Wood's Monograph on the Crag Mollusca {Pal. Soc). 

 The final classification of the Glacial series proposed herein has 

 already been given in the introductory chapter. No special 

 mention is made of these beds in Cambridgeshire, but among 

 the Post-glacial deposits the March Gravel receives some notice. 

 This is said to occur in the midst of the Cambridgeshire fens 

 and to form small islands rising out of the great level, "so that 

 there are no means of geologically testing its position\" 



The fauna they find to be rich in Mollusca and to resemble 

 that of Kelsea and Hunstanton in consisting entirely of recent 

 species, which with two exceptions are now living in British seas ; 

 Ostrea edulis is abundant at all three localities, and they think 

 there can be little doubt that the beds belong to the earlier or 

 Gyrena fluminalis part of the Post-glacial period. 



In 1872 E,ev. T. G. Bonney published some "Notes on the 

 Ely Clay-pit V and these are reprinted in the form of an ap- 

 pendix to his " Cambridgeshire Geology " (1875). 



After referring to the j^revious papers on the subject, he 

 states his adoption of Mr Fisher's view, in opposition to that of 

 Mr Seeley, and minutely describes the disposition of the strata 

 as seen between the years 1868 and 1872. Four sections are 

 drawn across the pit and a ground plan is also given ; by this 

 means he shows that, if the "fault hypothesis" be assumed, 

 no less than four faults are necessary to bring the beds into 



1 From this remark it is evident that Mr Wood does not believe in the sup- 

 posed intercalation of the gravels between two Bpnlder Clays at March. 



2 Geological Magazine, Vol. ix. p. '103. 



