502 S. V. Wood— The Valley System of 8.E. of England. 



Of the Great Oolite of France, M. Piette's figures are similarly 

 clefective ; of the three species, two apertures are given ; one is 

 decidedly without the groove of Purpura, the other has the posteal 

 extremity of the aperture out of the view of the spectator. The 

 Corallian species figured by M. Buvignier represent splendid speci- 

 mens all of which are destitute of the Purpura groove. The 

 apertures of Purpuroidea in the Great Oolite Monograph by Professor 

 Morris and myself are not so distinct as could be wished, but exhibit 

 nothing opposed to the views here stated. 



Upon reconsideration of the Figure 2, Plate VIIL, in the absence 

 of all knowledge of the dorsal surface of the last volution and the 

 small portion of the ornamentation exhibited upon Figure 2, I wish 

 to limit my remarks upon the presumed new species, to the shells 

 figured 1 and 4, also to the large specimen in my possession. 



YIII. — Further Eemaeks on the Origin of the Vaxley System 



OF THE SoUTH-EaSTERN HaLP OF ENGLAND, PROMPTED BY THE 



Eesult op a Boeing near Witham in Essex. 

 By Seaeles V. Wood, F.G.S. 



"N a paper in the Phil. Mag. for March, 1864, ''On the Forma- 

 tion of the River and other Valleys of the East of England," I 

 endeavoured to show by the aid of a rough map that the whole of 

 the hill and vale system of that part of England which lies east 

 and south of a line drawn from the Humber to the Cotteswold 

 Hills originated in a series of concentric arcs spreading from two 

 centres, one of which w^as near Canterbury, and the other just south 

 of the western end of the Isle of Wight ; the features thus produced 

 having been rendered more apparent by the denudation to which 

 the disturbances gave rise, and to which both at the time, and 

 subsequently also, these gave direction. With that map I gave 

 hypothetical lines of section along a radius of each of these systems 

 of concentric arcs to show the fold which, if my view of the subject 

 was correct, should be present throughout the whole line of each 

 arc; though of course this fold was concealed from observation, 

 except the chance occurred of there being an open section over it ; 

 and some two years afterwards I extracted from the one mile 

 to the inch Ordnance sheets of this part of England, and reduced 

 upon the ten miles to the inch map, the whole of these systems 

 of arcs in minute and accurate detail. This map was bound up 

 along with a Geological map which I had made of South Essex 

 in a MS. memoir on the Glacial Beds of the East of England, 

 which I presented to the Library of the Geological Society of 

 London, where I presume it still is. 



Though in various papers subsequent to that of 1864, both in the 

 Journal of the Geological Society and in this Magazine, I have 

 incidentally endeavoured to direct attention to the subject, the only 

 notice with which it has met, so far as I am aware, has been an 

 inci'edulous smile from geological acquaintances if I ventured to 

 allude to it; but between five and six years ago the Committee 



