8 NEW YORK STATE MUSEUM 



Central New York (Chenango, Otsego, Delaware and Cortland; 

 counties) . The legislature of 1899-1900 granted an appropriatioD. 

 for certain special investigations in the paleontology of the state^ 

 With the aid of this appropriation, it is purposed to study care- 

 fully, the relations of the Ithaca formation and its fauna to con- 

 tempoiraneou'S faunas at the east and west, as welll as to the faunas 

 immediately preceding and succeeding it in time. The Ithaca 

 group as a distinct geologic formation was recognized at an early 

 date and quite clearly defined by Lardner Vanuxem, the geologist 

 of the third district, though the name itself was first used by 

 James Hall. The fact seems not to have been clearly recog- 

 nized at that time that this Ithaca formation was coextensive 

 with that which was denominated in the fourth geologic district, 

 the Portage group, and also in a measure coextensive with the 

 so-called Oneonta sandstones of Yanuxem, in the eastern part 

 of the third district. The conditions with regard to these Ithaca 

 beds are essentially as follows. Lying above the beds of the 

 Hamilton formation and coextensive with the Portage forma- 

 tion on the west, they bear a fauna altogether distinct from that 

 of the Portage group and most intimately allied to that of the 

 Hamilton group beneath. So close indeed are the affiliations of 

 the Ithaca formation with the geologic formation which pre- 

 ceded it, and so intimate the connection of its organisms with 

 those of the Hamilton shales and sands, that all distinction be- 

 tween the fossils of this formation and those belonging to the 

 preceding period of time has been till quite recent years per- 

 sistently lost sight of in the reports on both the geology and 

 the paleontology of the regions above specified. Moreover, the 

 state museum is almost devoid of representatives of the peculiar 

 and characteristic fauna of the Ithaca group^ such specimens as 

 were lactually derived from it having been for the most part 

 referred in records and labels to strata of Hamilton age. The 

 Ithaca fauna and formation present a series of most interesting 

 and unusual problems in paleozoic stratigraphy. Bounded on 

 the east by formations of semi-marine or estuarine origin, on the 

 west by deposits containing a marine fauna invading the state 



