354 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Mar. 21, 



By repeated experiment it was found that water, whether quiescent 

 or running, deposited all the separated bivalve shells with the inside 

 or concavity upwards. The univalves are deposited with their mouths 

 upwards. These experiments are so simple and easily made, that 

 they need not be enlarged upon. 



As these positions do not prevail among the bivalves and univalves 

 of the crag, it may be observed that, although water may have trans- 

 ferred them to their present localities, it could not have been the cause 

 of their actual position. It was suspected that wind might have 

 effected this alteration. Shells being placed upon the ground as 

 water deposits them, and being blown upon with a pair of bellows, 

 immediately assumed their characteristic crag positions ; moreover 

 the umbo of each shell was turned in the direction of the current of 

 air. Repetition of this experiment on the sea-shore showed that the 

 shells w-ere at first carried along the beach, their umbones being 

 turned from the wind, till the shell was completely turned over, the 

 place of the umbo being reversed and occupying that point in the 

 circumference of the shell nearest the wind. 



The univalves, whose deposition in water with their mouths up- 

 wards was noticed above, on being subjected to a current of air rolled 

 over with their mouths downwards, the axis of their columellee being 

 generally at right angles to the direction of the wind. This experi- 

 ment w^as tried as well on the shore as in the house, and with similar 

 results in both cases. 



If the experiments are allowed to be conclusive, which it is thought 

 they fairly may, it will be evident that, as far as the observations go, 

 the water must have left the shells dry, and that wind then forced 

 them into their present position, and that no other wind than an 

 easterly one would have placed the umbones, or the longitudinal axis 

 of the univalves, as they are now found. This easterly wind must 

 have prevailed for a lengthened period of time, aiid experiment 

 would lead us to infer, with no inconsiderable force. 



[This paper was accompanied by a table of observations on the 

 position of the shells at various localities, and by an outline map 

 showing the supposed direction of the wind at each when the shells 

 were deposited.] 



March 21, 1849. 



J. G. Lynde, Jun., Esq., Rear Admiral Sir Thomas Trowbridge, 

 G.B., and M. Sylvain Van de Weyer, the Belgian Minister, were 

 elected Fellows of the Society. 



The following papers were then read : — 



1 . Description of erect Sigillari^e with conical Tap Roots, found in 

 the Roof of the Sydney Main Coal, in the Island of Cape 

 Breton. By Richard Brown, Esq. 



In addition to the erect trees from the Sydney coal-measures de- 

 scribed in the Journal of the Society, vol. i. p. 393 and vol. ii. p. 46, 



