10 TwEXTT-THiRD Report on the State Cabinet. 



belong to two distinct periods. The Gneissic and Granitoid 

 rocks, with some intercalated limestones, characterized by the 

 presence of extensive beds of magnetic iron ore in the connties 

 of Essex, Clinton, Franklin, Hamilton, etc., seem to be quite 

 distinct in character and age from the limestones and associated 

 rocks containing the specular iron ores of St. Lawrence and 

 Jefferson counties : the latter are apparently of newer age, 

 but whether belonging to the Huronian system or otherwise, it 

 may not be prudent with our present knowledge to express an 

 opinion. 



I have dAvelt upon these points in order to show that we have 

 yet much work to do before the limits of the formations, as 

 described in the New York Reports, can be properly indicated 

 u23on the map. Furthermore, I regard it as an imperative duty 

 to science and the State, that we should, by a careful examina- 

 tion of certain parts of the country, set these questions at rest, 

 and thereby afford the means for a reliable and complete guide in 

 the study of our own geological formations. 



The collection of fossils from the Potsdam sandstone, men- 

 tioned in the report of 1867, has been prepared and added to 

 the Museum in its proper order. This collection consists of the 

 common Lingula {Obolellaf) prima, a Lingulepis resembling 

 L. plnnaformis, a new species of Metoptoma, or a very depressed 

 form of Platyceras, and specimens of Conoccphalites minuta, — 

 the last three not previously in the cabinet. 



A detailed account of the additions to the Geological and 

 Mineralogical Departments will be found under the proper 

 head. 



A considerable addition has been made to the Collection of 

 Economic materials, as will be seen by the list of specimens. 

 I beg leave to call your attention again to the incommodious 

 arrangement of these materials, and the absolute need of more 

 room for so important a department. At the present time, the 

 building stones and marbles are arranged on shelves upon two 

 sides of the main hall of entrance, and so situated as to be 

 exposed to the constant handling of visitors. The iron ores arc 

 in the second story, and the only available S2)ace is upon a plat- 

 form so near the Hoor that they are exposed to the dust and 

 dirt of sweeping, and liable to be used as seats by inappreciative 

 visitors. This department is of sufficient importance to deserve 

 a proper room for its exhibition ; and, could all the materials be 



