124 NEW YORK STATE MUSEUM 



From these statements of Hall and Worthen it would appear that the 

 uppermost 35 to 40 feet of these beds alone may represent the Guelph. 



A few years later Hall explored the geology of the central and eastern 

 portions of Wisconsin, and the adjacent parts of Illinois. His results are 

 published in the Report of the Geological Survey of Wisconsin, 1862, v. i. 

 In this important work he separated [p. 67] the Racine limestone from the 

 Niagara limestone proper, as the upper member of the Niagara group. Of 

 the fauna of this limestone is said : 



Few of the species are identical with those in the Niagara group farther 

 to the east, or in the State of New York, though the Caryocrinus, in its 

 condition of casts, is not distinguishable from the C. ornatus of New 

 York, Kentucky and Tennessee. 



The species already identified with known species of the Niagara group 

 in New York in addition to the Caryocrinus, are Spirifer niagaren- 

 sis, S. radiatus and Strophomena rugosa, while we have a Spiri- 

 fer allied toS. sulcatus and an Illaenus closely allied to or identical 

 with L. (Bumastus) barriensis. 



In regard to its correlation it is stated : " It may be considered iden- 

 tical with the Le Claire limestone of Iowa, holding precisely the same 

 geological position, and containing some similar if not identical fossils, and 

 both limestones must be regarded as a part of the Niagara group." 



From this statement it is clear that, on account of the recognition of 

 New York Niagaran fossils in this Racine bed, Hall considered the Le Claire 

 limestone, which he here correlates with the Racine, neither as belonging to 

 the Onondaga salt group nor to a later stage than Niagaran, but as a mem- 

 ber of the Niagaran group. 



No mention was made in this report of the finding of Guelph fossils 

 in the Racine bed, but it is stated in the soth Annual Report of the New 

 York State Cabinet Natural History, 1867, p. 307: 



At the same time, we have recognized from Racine and adjacent locali- 

 ties, including Le Claire in Iowa and a single locality in Illinois, the following 

 species which are identical or very closely allied to those from Gait in 

 Canada West: Pentamerus occidentalis, an Obolus-like fossil, a 

 Favosites and a species of Amplexus which are identical in several locali- 

 ties, Cyclonema sulcata, Murchisonia logani, Murchisonia iden- 



