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' The Silurian System,' p. 555 : — " Mr. H. E. Strickland is the discoverer 

 of these ancient fluviatile deposits, which extend from Warwickshire into 

 the valley of the Severn, near Tewkesbury. He has found the remains 

 of twenty-four species of fluviatile shells, three of which are considered 

 to be extinct, and the bones of several species of extinct quadrupeds in 

 the gravel of the valley of Avon, an eastern tributary of the Severn (see 

 Geol. Proc. vol. ii. p. 111). Let us now see whether this phenomenon 

 be reconcilable with the view here given, of the comparatively recent 

 period at which the valley of the Severn is supposed to have lain under 

 the sea. The accumulations at and near Cropthorn constitute terrace- 

 like hillocks, from one to four miles distant from the present bed of the 

 Avon, above which their summits rise to a height of forty to fifty feet. 

 Mr. Strickland has traced these accumulations, which he first termed 

 " fluviatile diluvium," at intervals from Lawford in Warwickshire to 

 Defford in Worcestershire, and he has proved that they follow more or 

 less the course of the present Avon from north-east to south-west. 

 I refer to his interesting paper, shortly I hope to be published at length, 

 for the details presented at different localities, it being sufficient for the 

 present purpose to state the general results. I examined in company 

 with him two of the sections to which he refers. The clearest of these 

 is at Bricklehampton Bank, near Cropthorn on the Avon, where about 

 twenty feet of this detrital matter is arranged in the following manner, 

 resting upon the lias clay. 



" Upper portion, stiff reddish clay witli a few pebbles ; the central also 

 argillaceous but more marly, of green and purple colours, with some 

 yellow sand, and occasional irregular laminae of marl ; lowest, sand and 

 gravel, confusedly mixed up with lumps of marl, pebbles of quartz 

 (some five to six inches in diameter), broken chalk flints, much detritus 

 of the lias, and very rarely a fragment of oolite. 



" Many of the delicate shells mentioned in Mr. Strickland's list, were 

 found from the top to the bottom of this varied and almost coarse drift ; 

 being just as abundant in the underlying gravel as in the overlying marl 

 and clay. The bones of the quadrupeds occurred also through the mass, 

 though they were most abundant in the lower part. The discovery of 



