458 Geological Society. 



During the post-tertiary period, Mr. Smith is of opinion, an ele- 

 vating movement to the extent of 40 feet took place, and that at this 

 height, the relative level of sea and land remained stationary for a con- 

 siderable time, exceeding the present period of repose. The proof 

 of this, he states, is a magnificent range of inland sea cliffs, with beds 

 of gravel and sand interposed between them and the sea*. At first 

 Mr. Smith supposed that the beds of this period contained a small 

 proportion of unknown species ; latterly, however, he reduced the 

 number to one, the Area papillosa, which has within a few weeks 

 been discovered recent by Capt. Portlock on the coast of Ireland. 



During the existing geological epoch no change of level appears to 

 have taken place in the Basin of the Clyde f. 



To the paper is appended a list of the shells found in these beds, 

 but not known as inhabitants of the British seas, and of which the 

 following is a summary : — 



Fossil in the Basin of the Clyde. Fossil in other localities. Recent in the 



Tellina proxima Arctic Seas. 



Crassina multicostata Norway and Sweden. 



Witham i Wirk and Bridlington . . . Rothsay Bay. 



boreahs Dalmuir Arctic Seas. 



Mya truncata, var. ? Uddevalla; Canada ... St. Lawrence. 



-,. ^ Ti J- /"North Seas; coast of 



Pecten Islandicus | Newfoundland. 



Nucula oblonga. ^ 



antiqua. 



corbuloides Dundee; crag of Norwich. 



Mactra striata. 

 Saxicava sulcata. 



Panopaea Bivonse Crag; Sicily Yorkshire coast. 



-, ,. , XT 11 11 r North Seas; coast of 



Natica causa... Uddevalla | Newfoundland. 



glaucmoides. ^ 



fragilis Crag. 



Nassa Monensis Isle of Man, 



Buccinum granulatum ... Crag. 



striatum. 

 Trochus inflatus. 



Turbo expansus Arctic Seas. 



,;.,,.,, r North Seas ; coast of 



Velutmaundata | Newfoundland. 



Fusus Peruvianus Crag Arctic Seas. ' 



imbricatus. 

 Bulbus Smithii. 



Nov. 10. — An extract from a letter addressed to Dr. Andrew Smith 

 by A. G. Bain, Esq., dated Graham Town, Cape of Good Hope, Feb. 

 21st, 1839, and communicated by Ch. Darwin, Esq., was first read. 



The object of this extract is to announce the discovery, by Mr. 

 Martin Smith, of the piths and portions of the head of an ox in the 

 alluvial banks of the Modder, one of the tributaries of the Orange 



♦ Proceedings, vol. ii. p. 428. f Ibid.y vol. ii. p. 428* 



