1870.] NATURAL HISTORY SOCIETY. 451 



direct process of depositioa from watery solutions, in which they 

 were formed' by chemical re-actions. 



Dr. Dawson spoke, confirming the observations of Dr. Hunt, 

 which he had verified by microscopic examinations. He alluded 

 to the structure of crinoids, which in the fossil state were generally 

 filled with carbonate of lime, so .as to obliterate their pores and to 

 give them a highly perfect crystalline structure. The infiltratin'*- 

 silicate in the present case however showed, especially in delcal- 

 cified specimens, that these ancient crinoids closely resembled in 

 their minute structure the modern forms lately studied by Dr. W. 

 B. Carpenter and Professor Wyville Thompson, especially Coma- 

 tula. Figures of these delcalcified specimens were exhibited and 

 will be published. Dr. Dawson alluded farther to the process of 

 filling up the porous calcareous skeleton of the crinoids, which 

 was clearly shown to be prior to the cementing and consolidation 

 of the fragmentary limestone. 



A letter from Mr. John Mozer, giving an account of the dis- 

 covery of tamarack (^Larix Americana') stumps under the 

 surface in marshes at Upper Sackville, N.B., was read by the 

 Recording Secretary. 



Principal Dawson stated that remains of submarine forests had 

 been described by him in his Acadian Geology as occurinf more 

 than twenty feet below high-water mark on the coast of Nova 

 and that these and Mr. Mozer's observations tended to corroborate 

 the view that a gradual subsidence of the land had taken place 

 and was still being effected over a considerable area in Nova 

 Scotia and New Brunswick. 



Mr. J. P. Clark exhibited and presented to the Society a series 

 of engravings of incised rocks found in Northumberland and 

 Argyleshire. A discussion ensued as to the meaning of the 

 markings figured in the drawings. Some members thought they 

 were intended to commemorate funeral rites, or other reli'dous 

 ceremonies; others thought they were ground plans of villages or 

 camps. 



Public Lectures. 



The following is a list of the Somerville lectures, with the 

 names of the authors and the dates at which the lectures were 

 delivered. 



1. Jan. 19th, 1871. On the Primordial Period in Geology. 

 By Principal Dawson, LL.D., F.R.S. 



