359 



ever, to be erroneous, as the soil of which it is composed, which 

 is a yellow sand, extends some miles inside of it. He thought it 

 had probably been formed under water in a similar way to the 

 submarine ridges found in the vicinity of Nantucket, and the 

 Oesars which have been described by Brongniart as occurring in 

 the north of Europe. 



Mr. Stodder said he did not regard the existence of a sandy 

 soil inside of the ridges of Lake Erie sufficient evidence that 

 they are not old beaches, which he himself believed them to be. 

 Around Chelsea Beach, in Massachusetts, there is a ridge fourteen 

 feet high, through which pebbles seem to have worked their way, 

 just as they are described by Mr. Whittlesey as having done at 

 Lake Erie. Within the outer ridge of Chelsea Beach are two 

 others like terraces. From the existence of the remains of trees, 

 there is evidence of the subsidence of the marsh within at a 

 comparatively recent period. 



Mr. Desor replied, that he agreed with Mr. Stodder in the 

 view which he had taken of Chelsea Beach. He thought, how- 

 ever, that the difference of level of the Ridge Road at different 

 places was incompatible with the supposition of its having been a 

 beach. The ridges near Toronto, on the contrary, had been 

 regarded by Mr. Whittlesey as beaches, from the fact of their 

 base line being level.. 



Mr. Stodder said, that the unequal elevation of different parts 

 of the Ridge Road was not incompatible with the theory of its 

 having been a beach, if it be supposed to have been raised to 

 its present position. The elevation of so extensive a tract to the 

 height of five or six hundred feet could hardly have occurred 

 without producing inequalities at different places, as great as are 

 found, of some thirty or forty feet. If the ridge had been left by 

 the subsidence of Lake Erie, it would probably have been level. 



Mr. Wells alluded to the occurrence of Septaria on the 

 eastern bank of the Connecticut as an interesting fact in its 

 bearing upon the comparative age of American and Euro- 

 pean deposits. Li England the Septaria are characteristic 

 of the lower lias. 



Dr. A. A. Gould presented descriptions of sixteen species 

 of Melania, which had been regarded as new by Mr. J. G. 



