102 [May, 



transmittlns the first numbers of the " Canadian Naturalist and Geolo- 

 gist/' and desiring exchange. Tiiis letter was referred to the Committee 

 on Proceedings. 



From Mr. Abraham Sager, dated Ann Harbor, Michigan, 5th May, 

 185G, transmitting for publication in the Proceedings, a paper, entitled, 

 ''Descriptions of Articulata, supposed to be new;" which was referred 

 to a Committee consisting of Drs. Leidy, Hallowell, and Bridges. 



Mr. Isaac Lea presented a paper for publication in the Proceedings, 

 entitled, " Descriptions of four New Species of Exotic Uniones;" which 

 was referred to a Committee consisting of Drs. Wilson and Bridges, and 

 Mr. Hanson. 



Mr. Charles E. Smith remarked in relation to the specimens of iron 

 ore presented by himself this evening, that the three leading varieties 

 of the ore, known as the Baltimore ore, were shown in the specimens. 

 The bed lies on the west side of Chesapeake Bay, runs parallel with it, 

 and is about fifty miles long. It is of white clay underlying the Eocene 

 deposit. The ore lies in nodules like the brown hsematite. In the most 

 valuable bed, this ore is associated with large quantities of mineral 

 charcoal, which seems to be always in broken masses. Mr. S. bad never 

 seen any traces of plants. There is no other deposit of iron ore in the 

 neighborhood. The iron made from this ore is remarkable for its great 

 strength. Mr. S. considered the deposit as remarkable, being the only 

 one of which he was aware, in which the lithoid carbonate of iron exists 

 out of the coal measures. 



May 20lh. 

 Mr. Ord, President, in the Chair. 



Dr. Bridges, referring to the specimens of lithoid carbonate of iron 

 exhibited at the last meeting, gave the following as the probable theory 

 of the formation of this ore. Iron pyrites by exposure would be con- 

 verted into a sulphate of the protoxide with some sesquioxide of iron. 

 By contact with lime these oxides would be precipitated, the protoxide 

 rapidly becoming sesquioxide. The contact of organic matter would 

 reduce the sesquioxide again to protoxide, which would combine with 

 the carbonic acid evolved during the fermentation of the organic matter. 



Mr. Cassin announced the arrival in this country and the presence 

 this evening of the Baron Von Miiller, who proposes to visit Texas, 

 Mexico, and Central America, and who is desirous of afibrding to the 

 Academy any aid in his power. 



Dr. Leidy remarked that he had just returned from a visit to St. 

 Louis, and thought that the members would be gratified to learn that 

 an " Academy of Science " had been organized in that city, whose ob- 

 jects were similar to our own. The Academy commences under the 

 most promising prospects ; and it occupies a highly favorable position 

 in our country for the formation of a cabinet of natural history. It 

 has recently received a large and very valuable collection of fossils, ob- 

 tained by Dr. F. V. Ilayden from the region of the Upper Missouri. 



