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familiar with the locality. The letter was read by the 

 Secretary. It confirmed Mr. Desor's statements of the 

 existence of fossil shells in the coarse drift of Long Island. 

 Some of them are of existing species and have been found 

 at Bedford, two miles east of Brooklyn Ferries, at a depth 

 of eighty feet. The letter concluded as follows : — 



" You will perceive that my views, founded on the opportuni- 

 ties which have long been and are now constantly afforded for 

 examining new sections of the drift in this vicinity, are quite dif- 

 ferent from those to which you have referred ; and that I con- 

 sider the greatly protracted period in which this drift was accu- 

 mulated as posterior to the so-called post-tertiary deposits. I 

 cannot, however, claim to speak authoritatively in these matters." 



Mr. Desor said, that he dissented from Mr. Redfield's 

 opinion as to the age of the deposit in question ; he re- 

 garded it, as well as the deposit at Point Shirley, as only 

 an exception to the common rule of the quaternary forma- 

 tion, and not enough to constitute a distinct epoch. 



Dr. Gould stated, that Dr. Wood, of Portland, had re- 

 cently discovered at Portland a deposit similar to that in 

 Brooklyn. 



Prof. Rogers asked whether the strata, containing shells 

 at Brooklyn, are immediately over a scratched surface. 



Mr. Desor replied, that he could not say positively, but 

 he was satisfied in his own mind that such is the fact. It 

 had been frequently asserted that the drift in the neighbor- 

 hood of Boston is glacial. The fact of its containing shells 

 is incompatible with this view. Near Milton, Mass., the 

 coarse drift is above the clay ; an arrangement similar to 

 that of the Laurentian deposit. 



Dr. Jackson said, that the most extensive deposit of 

 marine shells that he had seen was near Portland, where 

 they were found, of extinct species, associated with the 

 shells of crabs. Many of the shells were very delicate, and 



