214 C. S. Prosser — Upper Hamilton and 



There is one mistake in reference to the stratigraphic order 

 of the groups of the above list. The " Cazenovia group " 

 belongs below instead of above the Tully limestone. This 

 error was corrected by Vanuxem in his final report, where 

 under the heading of the Hamilton, the " Cazenovia group " 

 is given as one of its divisions.* 



To one who is not familiar with the geological outcrops 

 near Cazenovia, a glance at the geological map of New York 

 of 1843, or the one showing the " Geographical distribution of 

 the Tully limestone in central New York " by Professor S. Gr. 

 Williams,t will show the exposures of Tully limestone as 

 considerably south of Cazenovia. Of course the " Black 

 slate " represents the Marcellus shale, while the " shales near 

 Apulia," and the "Sherburne group" are parts of the Hamil- 

 ton stage as stated by Vanuxem.:); It is interesting to note 

 that the term " Sherburne group " of Conrad is not the same 

 as the " Sherburne flagstone and shale " of Vanuxem as will 

 be seen from an attentive examination of his final report. § 

 The Sherburne flagstones of Vanuxem are a mass of sand- 

 stones in the Chenango Valley above the horizon of the Tully 

 limestone, which are mostly non-fossiliferous and are synchron- 

 ous with the lower part of the Portage as exposed farther west. 

 Below these flagstones are argillaceous shales which contain an 

 abundance of Hamilton fossils, as for instance in the shales at 

 Pexford or Sherburne falls. The same zone is well exposed 

 in the gorges near Smyrna where the Sherburne flagstones 

 form the top of the high hills, and most of the species which 

 Conrad gave as belonging to the " Sherburne group '' were from 

 "near Smyrna." The following, which are now all well 

 known Hamilton species, were named and described : 



Nuculites ohlongatus, N~. rostellatus, N. bellistriatus [now 

 Nuoula bellistriata\ Orthonota undulata, Cypricardites 

 oblonga [now regarded as a synonym of Modiomorpha con- 

 centrica (Con.) Hall], and C. rugosa [now Goniophora rugosa 

 (Con.) Miller].| 



Above this zone Conrad placed the Tully limestone, but 

 apparently no representative of the Genesee shale is given. 

 The highest rocks are the Oneonta group which are supposed 

 to have been named from exposures near that town. Nucu- 

 lites cuneiformis, W. maxima [now Balwoneilo maxima (Con.) 

 Hall], and Cypricardites carinata [now Goniophora carinata 

 (Con.) Hall] were named and described from this formation at 



*Geol. N". Y., Pt. Ill, p. 150. 



f Sixth Ann. Rep. State Geologist [N. Y.] for 1886; map following p. 28. 

 {Geol. N. Y, Pt. Ill, p. 150. 



§ See the explanation of the names that had been used for different parts of 

 the Hamilton on p. 150, and the same for the Portage on p. 172. 

 || 5th Ann. Rep. Palaeontology N. Y., pp. 50-54. 



