133 Association of An.erican Geolog'xsls and Naturalists. 



America; the terraces of the same basin might have corresponding 

 levels, but terraces of different basins could not possibly have the 

 same level above the ocean tide. Professor Silliman hoped that 

 members would turn their attention to this subject. He had lately 

 vi.-ited the terraces in New Hampshire, and had an opportunity to 

 examine their internal structure through the cuttings of the railroad 

 through them. They presented a very beautiful appearance. Mr 

 Hall, late geologist of tlie State of New York, said that the terraces 

 along lake Ontario, had an almost uniform height on both the 

 Canadian and American shores. M. Desor, a French gentleman, 

 stated that the terraces in Finmark were nearly of the same height, 

 but not perfectly horizontal, which was presumed to arise from the 

 subsidences. 



On the motion of Pi'ofessor Tellkampkf, the committee appointed 

 to investigate the subject, whether platina had been found in the gold 

 districts of the south, were authorised to continue their investiga- 

 tions, and report at the next annual meeting. 



Wednesday'' s Proceedings, 



Professor Silliman, senior, exhibited a specimen of uncrystallised 

 corundum from North Carolina ; and stated, that he had received a 

 specimen of this same mineral many years since from the same 

 state. 



Mr Clingman of North Carolina, who had brought this specimen 

 from North Carolina, gave an account of the circumstance of its dis- 

 covery, which placed the statement that it was a native specimen 

 beyond a doubt. 



A paper was read by Mr TV. C. Redfield of New York, " on the 

 remains of marine shells of existing species, found interspersed in 

 deep portions of the hills of drift and boulders, in the heights of 

 Brooklyn, on Long Island, near New York city." These remains 

 had long since attracted the attention of Dr Mitchell, and other na- 

 turalists of the vicinity, but the true character of the formation, and 

 the jieculiar positions in which the shells were found, were not dis- 

 tinctly known to geologists. 



It fortunately happened that M. Desor and Count Portalis, while 

 on a visit to Brooklyn a few months since, discovered fragments of 

 these I'emains in the great masses of boulder-drift in South Brook- 

 lyn, through which the new streets are being excavated. At their 

 invitation, Mr Redfield had examined the place in company with 

 Professor Agassiz, and had obtained a variety of specimens, which 

 were found at depths varying from twenty-five to forty feet below 

 the original surface of the hills, in which they were embedded. 



Since that occasion, Mr Redfield has found similar remains in 

 those hills about two miles northward from the first locality, and 

 has collected numerous specimens, which he exhibited to the meet- 

 ing, together with samples or fi'agments of the original beds inclosing 



