218 Association of Geologisss and JYaturalists. [Oct., 



the Alps, whose general appearance agreed with what is observed 

 in this country. 



Prof. Silliman in answer to the doctrine just advanced, observed 

 that the cause could not apply to, nor explain the phenomena of 

 the drift of his country. 



Prof Henry D. Rodgers referred to the different periods of drift, 

 that of Montreal Island as a more recent accumulation of drift, 

 and which was derived from the post pleiocene marine deposit of 

 the valley of the St. Lawrence and Lake Champlain, and as dis- 

 connected with the great period of drift which was moved forward 

 anterior to the clay deposits formed in a period of repose. 



Remarks hy the Editor. — There are two or three interesting 

 points brought out by Mr. Redfield, and by the remarks of gen- 

 tlemen who engaged in the discussion. 



L That there is little or no evidence of a change of climate 

 about the drift period. 



2. That a direct communication formerly existed in the course 

 of the valleys of the Hudson river and Lake Champlain, and which 

 would necessarily make New England an Island. 



3. That at least two periods of drift must be recognized; one 

 of which was anterior to the deposit of clay in the valleys first re- 

 ferred to, the second that during which the shells on the summit 

 of Montreal Island and Long Island were deposited. 



Prof J. W. Bailey read a paper upon the structure of anthra- 

 cite coal. Thin slices of coal showed very plainly the vegetable 

 tissue. But there was no evidence that arborescent plants had 

 entered into the formation of coal — it was only the deciduous and 

 soft portions which had been converted into coal. Anthracite 

 coal had been examined — soft coal containing so large a quantity 

 of bitumen could not so readily be tested. 



A few remarks passed between Professor Bailey and Mr. Tesch- 

 macher, upon an apparent discrepancy in their views in relation 

 to the subject of coal. 



Professor Hitchcock read a paper, being an attempt to discrim- 

 inate the animals which had made the fossil footmarks in the Con- 

 necticut valley. He had discovered forty-seven species in nine- 

 teen localities. At some length, he urged the propriety of his 

 giving names to the birds as well as to the footprints. He then 

 stated the peculiar characteristics of the footmarks which led him 

 to assign the names that he had done, to the birds, — such as thick 



