342 



cedently to those which rest upon it : that it was not injected laterally, 

 as Professor Sedgwick proved to be the case with the whin at High- 

 Teesdale, but was produced by an overflowing of lava during the 

 deposition of the limestone group 5 and that the alternations of basalt, 

 limestone, sandstone or shale, where they occur, indicate a succes- 

 sion of overflowings at different periods. 



A paper was then read entitled " Zoological observations on a new 

 fossil species of Chelvdra from CEningen," by Thomas Bell, Esq. 

 F.G.S. F.R.S., &c. 



In this notice the author gives a description of the osteological 

 structure of a fossil tortoise, which was found in the upper quarries of 

 the lacustrine limestone of CEningen, near the lake of Constance. 



He proves that the fossil belongs to the genus Chelydra, by 

 showing that it possesses the characters which distinguish this genus 

 from every other form of Testudinata ; but he determines, by a table 

 of comparative measurements, that the CEningen specimen is a 

 species distinct from Chelydra serpentina or the snapping tortoise of 

 North America. 



He concludes his memoir by describing the habits of the recent 

 animal. 



Jan. 18. — Nathaniel Thomas Wetherell, Esq., of Highgate, Mid- 

 dlesex ; Captain T. E. Sampson, 22nd Regiment of the Bengal Native 

 Infantry 5 The Hon. and Very Reverend the Dean of Windsor, —were 

 elected ordinary Fellows of this Society ; and M. Erlert Mitschir- 

 lich was elected Foreign Member of this Society. 



An essay" On the geological structure of the Crimea," by Baron 

 Stanislaus CIiHudoir, communicated by Sir Alexander Criehton, 

 K.W.S. F.G.S. F.R.S., was read. 



The peninsula of the Crimea is described by the author as being 

 naturally divided into two districts 5 — that of the plain, and that of 

 the mountains. The plain commences at the isthmus and terminates 

 near Simpheropol, following the direction of the mountains from 

 south-east to north-west. It is level, and watered by very few 

 streams, which are generally dry during the heats of summer. The 

 surface is so uniform and unbroken that the author did not find a 

 single opportunity of observing any rock below the superficial stra- 

 tum, which belongs to the most recent formations, and consists of 

 shells, analogous to those now living in the neighbouring seas, ce- 

 mented by sand, lime, and marl. The mountainous district extends 

 along the sea-shore, varying in breadth from 15 to 70 wersts, the 

 principal ranges being those of Ischaterdagh, and Yaila. The rocks 

 of which they are composed the author considers as belonging to the 

 following formations : — 



1. Cretaceous deposit with large strata of flints, but which resembles 

 the chalk neither of England nor of France, being always marly. It 

 is the principal formation near Karasoubazar. 



2. A limestone accompanying the above, containing in the neigh- 

 bourhood of Simpheropol great numbers of univalves, and very large 

 oyster-shells. 



