283 Geological Society. 



fossil species of Chelvtlra from QSningen," 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 Cheiydra, 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 Cheiydra serpentina or the snapping tortoise of 

 North America. 



He concludes his memoir by describing the habits of the recent 

 animal. 



Jan. 18— An essay" On the geological structure of the Crimea," 

 by Baron Stanislaus Chaudoir, communicated by Sir Alexander 

 Crichton, 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 ; — 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. 



3. Another calcareous rock, of a compact close grain, and yellowish 

 smoky colour. It is found near Soudak. 



4. The jura or oolitic formation, which the author considers to 

 rest on hard, cellular, magnesian limestone (rauchwacke) and on 

 mountain limestone. 



5. Rauchwacke, porous, globular, and of a yellow colour, occurring 

 in perfectly horizontal strata on the road from the German colony of 

 Rosenthal to Koutschouk-Kousin. 



6. Cavernous limestone, which, as well as the rauchwacke, is 

 found in parallel strata of very great extent, and forms chains of hills, 

 which are less elevated than those of the magnesian limestone. 



7. Variegated sandstone in alternate thin strata of a green, brown, 

 red, and yellow colour : it is well developed at Sably and Alma. 



8. Con- 



