54:6 Geological Society : Mr. Pearce on Ammonites^ 



prevent its being " mixed up in any way with the subject of this paper, 

 or the inferences it contains ; " and lastly, he wishes it may be clearly 

 understood, that while he advocates the explanation of many geolo- 

 gical phenomena by means of pressure from without, he does not 

 propose that all geological disturbance should be attributed to it ; 

 nor does he deny that many, and more especially the most consider- 

 able, irregularities in the structure of the earth may and must be 

 assigned to other causes. 



" Notice on the occurrence of Plants in the Plastic Clay of the 

 Hampshire Coast," by the Rev. P. B. Brodie, F.G.S., was then read. 



The cliffs to the east and west of Bournemouth are composed of 

 horizontal strata belonging to the plastic clay formation. East of 

 the town they consist of white and yellow sands, the former con- 

 taining fragments of wood. Further along the shore the cliffs arc 

 higher, and beds of clay full of vegetable remains appear under 

 the sands. About half a mile beyond, a stratum of fine white sand, 

 three or four feet thick, situated near the middle of the cliffs, con- 

 tains impressions of ferns ; and a layer of sand and clay is full of 

 small leaves. The subjacent strata of clay are separated by thin 

 layers of vegetable matter. Somewhat further, beds of white and 

 yellow sand and sandy clay abound with beautiful leaves, and the 

 surface of the strata is in some places covered with a thin layer of 

 iron-sand containing impressions of ferns. In most cases, the vari- 

 ous- coloured sands are divided by beds of clay, and their fossil con- 

 tents are distributed in layers at rather distant intervals. Mr. Brodie 

 did not discover any shells. Several of the fossil plants are stated 

 by the author to belong to the Lauracea and Amentacea; but he 

 says that these, as well as others which he arranges among the 

 Characea and Cryptogami, and some of which he has not determined 

 the characters, are all geaerically distinct from any British plant, and 

 belong to those of a warmer climate. When the sandstone is freshly 

 broken the epidermis of the fossil frequently peels off, leaving the 

 impression of only the fibres. These remains often form masses of 

 some thickness ; and, from their state of preservation, must, the 

 author states, have been deposited tranquilly beneath the waters. 



A.paper " On the Mouths of Ammonites, and on Fossils contained 

 in laminated beds of the Oxford Clay, discovered in cutting the Great 

 "Western Railway, near Christian Malford in Wiltshire." By J. 

 Chaning Pearce, Esq., F.G.S., was lastly read. 



Mr. Pearce commences by stating, that his attention was first di- 

 rected to this part of the railway by the impression of a crushed 

 Ammonite procured at Cheltenham in April 1841, but that he was 

 prevented from examining the locality for three or four months. 



The following section of the beds is given by Mr. Pearce : — 



1 . Alluvial soil 2 feet. 



2. Gravel 8 ... 



3. Four or five bands of laminated clay, al- 



ternating with sandy clay, almost en- 

 tirely composed of broken shells. ... 6 ... 



4. Clay, containing Gryphaa bilobata. 



