210 REVIEWS 



page, it is possible that another part containing these papers is con- 

 templated. 



i. The Stratigraphic and Faunal Relations of the Oneonta Sand- 

 stones and Shales, the Ithaca and Portage Groups in Central New York. 

 By J. M. Clarke. Pp. 27-81, plates I-VII and two maps. "This report 

 presents a revision and summary of observations previously made by 

 the same author with reference to the position of the Oneonta sand- 

 stones and their extent westward from the Chenango River, and adds 

 thereto more recent data bearing upon the passage of the Ithaca fauna 

 in the region of its highest development in Cortland and western 

 Chenango counties into the typical fauna of the Portage group." 



" The Portage group is a series of arenaceous deposits representing 

 the geological time which elapsed from the close of the Hamilton 

 period (including the Tully limestone and a portion of the Genesee 

 slate when present) to the opening of the Chemung period. The 

 typical and unmixed fauna of its westerly sections has little organic 

 relation to the proper fauna of the Hamilton shales, the Chemung 

 fauna succeeding, or the Ithaca faunas adjoining on the east. It is an 

 exotic fauna, evidently derived from the west and making its first 

 appearance in the Genundewah limestone of the Genesee slates. It is 

 the Naples fauna ." 



"The fauna of the central and east-central sections is an indigenous 

 fauna, and its organic composition stands in the closest relation to 

 the fauna of the Hamilton group, but in its later manifestations 

 assumes many characters of the Chemung fauna. In the Chenango 

 Valley and eastward the upper portion of the deposits of this age is 

 represented by the Oneonta group with a very sparse fauna and well- 

 characterized strata. In Chenango county they replace the higher 

 beds bearing the Ithaca fauna." 



2. The Classification and Distribution of the Hamilton and Chemung 

 Series of Central and Eastern New York. By C. S. Prosser. Pp. 83- 

 222, plates I-XIII and one map. The investigations described in this 

 report were undertaken in order to trace the boundaries of the Oneonta 

 group of sandstones and shales and to elucidate as far as possible the 

 division line between the Hamilton group and the overlying strata. 

 This latter is a perplexing problem because east of the Chenango 

 River the Tully limestone and Genesee slate are wanting and the 

 sandy shales of the Hamilton group pass upward into those of the 

 Ithaca group with slight lithologic changes and with alterations of 



