The Conversazione. 307 
Mr. Mackniel, for many years known as an active local Geologist, 
and-who has kindly undertaken the office of curator to our temporary 
museum, was also an observer on the spot. Professor Morris de- 
scribed the fossil remains: and to these three gentlemen alone is 
due the eredit of preserving any notes of the Geology of the Wilts, 
Somerset, and Weymouth Railway. 
Since Mr. Mantell’s time, the geology of Westbury has attracted 
much attention from the important discovery of the valuable iron ore. 
Mr. Cunnington took this opportunity of correcting an error in the 
_ published section.!. The iron of Westbury is zo¢t derived from the 
Lower Green Sand, which stratum is altogether wanting at West- 
bury; but from certain beds of pisolitic shale belonging to the 
Kimmeridge Clay. In support of these views, he stated that the 
shale from which the iron is smelted contains numerous layers 
of the Ostrea deltoidea, the characteristic fossil of the Kimmeridge 
Clay, and that to the south of the works the iron shale is covered 
with a bed of pure Kimmeridge Clay, with all the usual fossils of 
that stratum. : ‘ 
He further drew attention to the remarkable fact that these 
Kimmeridge Clay beds yield in the furnaces both zinc and titanium ; 
_ the former in the metallic state, the latter as titanium cyanide. 
Unfortunately neither occurs in sufficient quantity to be of value— 
the zinc on the contrary is injurious to the furnaces. He mentioned 
that both these metals are absent from the Seend iron ore, which is 
Lower Green Sand. Mr. C. also suggested that the presence or 
absence of these metals might aid the geological chemist in deter- 
mining the ancient rocks from which the Kimmeridge Clay and 
other secondary strata derived their origin. 
Regarding the Oxford Clay of Trowbridge, Mr. Mantell mentions 
that the abundance of fossils in some of the beds is truly astonishing, 
especially the immense numbers of the shells and osselets of Cepha- 
lopoda.? ‘Often in exposing an area of clay or shale many yards 
in extent, the whole surface was studded with the glittering pear- 
ly shells of Ammonites of various species, and the numerous 
1 Geol. Jour., vol. vi., 1850. 2 Ibid, p. 314. 
_ yOL. XIII.—NO. XXXIX. Z 
