18 
It is here, as in other parts, thickly covered with Oak ; and here also, as in other parts of its 
course through the interior, it seems to be distinguished by considerable plains, which in this 
district are most remarkable on each side of the Forest Ridge, between the sands of that hill and 
those nearer the Chalk hills, and constitutes what may be called the deepest parts of the Wealds 
of Kent and Sussex. 
Organized Fossils contained in the Septaria of a thick Stratum of Clay, incumbent on rock, 
are frequently the same as in the top of the rock itself; therefore, figures of these need not be 
repeated. The Melania of the Oak-tree Clay is the same species as M. Heddingtonensis, which t 
is common to the top of the Coral Rag rock. 
Cockscomb Oysters are also common both to that rock, and to the Septaria above ; in fact 
those large C lay-balls found plentifully in the deep cutting of the north Wilts Canal seemed to 
partake both of the inhabitants of the rock above, and of that below the Clay ; the Trigonia 
of the Clay-balls being the same species as those large ones which compose the chief part of 
some beds of stone, about four feet thick, near the bottom of the Swindon rock. 
It may at first appear that the identification of Strata, by the organized Fossils they contain, 
would in such cases be somewhat doubtful ; but in the course of the work I shall make further 
remarks on such apparent repetitions, which will rather show the great utility of them, to well- 
sinkers and others, concerned in deep excavations in these thick Strata of Clay, abounding 
with alternations of stony matter and organized Fossils. 
The flat Oyster, fig. 6, in a layer, is so common in the ditches of this land, as to be called 
Clay Shells . 
None other of the organized Fossils are found but in deep excavations. 
FIG. 
1 Melania Heddingtonensis 
2 Turbo - 
3 Trochus - 
4 Ampullaria 
5 Chama - - - 
6 Ostrea delta 
7 Ammonites 
8 Yenus 
0 Terebratula 
ORGANIZED FOSSILS . 
North Wilts Canal. 
North Wilts Canal. 
North Wilts Canal. 
North Wilts Canal. 
Bagley Wood Pit. North Wilts Canal. Well 
near Swindon, Wilts and Berks Canal. 
Canal at Seend. Well near Swindon, Wilts and 
Berks Canal. North Wilts Canal. Bagley 
Wood Pit. Near Shrivenham. Even Swindon. 
Wotton Basset. 
North Wilts Canal. Well near Swindon, Wilts 
and Berks Canal. 
North Wilts Canal. 
Bagiev Wood Pit. 
and Berks Canal. 
Well near Swindon, Wilts 
North Wilts Canal. 
