W. SHONE ON THE GLACIAL DEPOSITS OE WEST CHESHIRE. 385 



and rediscovered by Mr. Shrubsole. It is worthy of note that the 

 Turritellce and the other Gastropoda of the Middle Sands do not 

 yield any Microzoa ; the sand within them is azoic. Mr. De Ranee, 

 F.G.S., informs me that he has examined the sand from within the 

 Gastropoda occurring in the Middle Sands of Blackpool with like 

 results. This fact indicates that the conditions which obtained 

 during the deposition of the Middle Sands were different from those 

 under which the Upper and Lower Boulder-clays were formed ; for 

 in these for the most part the Gastropoda are filled with a fine 

 greyish-white sand abounding with Microzoa, though the shells lie 

 imbedded in a matrix of red clay. I shall attempt to give the ex- 

 planation of this further on. 



The shells from the Middle Sands and Gravels are, as a rule, more 

 friable and much more rolled than those from the Boulder-clays. 



In the section the sand was proved to a depth of 35 feet. There 

 was not even a pebble, much less a boulder, found in it. The con- 

 spicuous absence of polished and striated erratics in the Middle 

 Sands and Gravels is a marked feature. This sand is of the same 

 horizon as that which covers the flanks of the Cheshire hills in the 

 neighbourhood of Delamere,in which Sir Philip Grey-Egerton in 1835 

 and 1836 found marine shells, viz. Cardium edule, Mureoc erinaceus, 

 and Turritella terebra. Sir Philip Grey-Egerton recently informed me 

 that the pits at Wellington and Norley Bank, from which he 

 obtained these shells (Proc. Geol. Soc. vol. ii. pp. 189, 415), have 

 been long since closed. 



The most interesting part of the section was that exposed near the 

 accommodation-road bridge leading to a farm (see figure, p. 384. It 

 is the next after the Trafford-road bridge to cross the line. Here the 

 Lower Boulder-clay was exposed for a distance of 150 yards, and 

 varying from 2 to 5 feet in thickness. It was evident, from the eroded 

 surface of the Lower Boulder-clay at its junction with the Middle 

 Sands above, that it was but a relic of the base of it which was here 

 preserved, for the Lower Clay graduated into the coarse red sand of 

 the disintegrated Bunter Sandstone immediately beneath. I have 

 used the term Lower Boulder-clay; but the word "clay " must not be 

 understood literally, as the stratum, though of the horizon of the 

 Lower Boulder-clay, was composed half of dark red clay and half of 

 coarse red sand from the rock beneath, mingled (but not mixed) 

 confusedly together, especially at the base. No shell-fragments 

 were observed. The erratics, however, abounded, being very much 

 more numerous and very much larger than those in the Upper 

 Boulder-clay before described, although of the same kind of rocks in 

 both. The boulders in the Lower Clay consisted principally of 

 Eskdale granite and Ennerdale syenite (identified by Mr. Mack- 

 intosh), decomposed greenstone, porphyry, Silurian grit, and (more 

 rarely) Carboniferous Limestone, Millstone Grit, Keuper sandstone, 

 gypsum, &c. Nine tenths of the erratics were polished and striated, 

 the majority on two or more sides, a few only on one side, and 

 striated along the longer axis. 



The Lower Boulder-clay of Dawpool, Cheshire, described by Mr. 



