NEWTON : CONCHOLOGICAL FEATURES OK LENHAxM SANDSTONES. 57 



The fossils known in the various museum collections have been 

 mostly obtained from a large dis-used chalk quarry situated about 

 half-a-mile to the north of Lenham, of which an excellent sketch may 

 be consulted in Mr. Reid's "Pliocene" memoir of 1890, showing the 

 vertical positions assumed by the fossiliferous sandstone-pipes seen in 

 the limestone exposure. It has been generally recognised that such 

 deposits represent the remnants of a marine Tertiary formation 

 belonging to early Pliocene times, although my own investigations 

 have led to somewhat different results, and I am more inclined to 

 refer them to the latest division of the Miocene period. 



The organisms occur as casts and cavities in the sandstone, and 

 are frequently in a fragmentary condition, rendering their determina- 

 tion extremely difficult. The walls of the cavities, however, often 

 retain sculpture characters, so that it is possible by the aid of wax 

 impressions to obtain reliable evidence as to external details which 

 may be safely used for purposes of identification. To Mr. Clement 

 Reid, F.R.S., we are mainly indebted for most of our later knowledge 

 of the Lenham fauna, his researches forming part of the "Pliocene" 

 memoir before mentioned. At that time Mr. Reid had obtained an 

 important series of fossils from the Lenham beds for the Museum of 

 Practical Geology, which, after being determined, were systematically 

 referred to in the memoir. In order to facilitate my studies on this 

 subject and to enable me to determine certain collections of similar 

 fossils in the British Museum, especially that formed by Mr. Graham 

 AVallas, I was very kindly allowed to loan this valuable type collec- 

 tion made by Mr. Reid. During my studies in this direction, it has 

 been necessary to introduce a certain amount of revision, both among 

 the genera and species as laid down in Mr. Reid's memoir. The 

 larger amount of material available at the present time has also 

 resulted in the determination of additional species, so that the shells 

 are regarded as numbering 77 species, which include i Scaphopod, 

 T^2 Gastropods, 43 Pelecypods, and i Brachiopod, whereas Mr. Reid's 

 conchological list embraced 65 species, consisting of i Scaphopod, 

 27 Gastropods, 36 Pelecypods, and-i Brachiopod. Among the 32 

 Gastropods now recognised, a new species has been described under 

 the designation of Riiigiculella lenhamensis. In view of the fact that 

 no figures have yet been published of Lenham fossils, I have had 

 prepared some photographs of the more important shell-remains, 

 which on account of their reddish-brown colour and their more or less 

 obscure character have not been particularly successful ; yet it is 

 hoped they may serve a useful purpose in stimulating the interest of 

 the student who desires to pursue further researches on the conchology 

 of these little-known beds. 



