Clarke — Oneonta, Ithaca and Portage Groups. 



41 



[Bell&rophon Mae nr. 



From this quarry it is about seventy-five feet to the top of the hill, and 

 the exposures in this distance have not yet been examined by Mr. Williams. 

 The total height of the hill proves from the measurements given in this sec- 

 tion to be about 400 feet. 



It is clear that the same fauna permeates all these sections. If we allow 

 150 feet for the southerly dip of the rocks in the interval of three miles 

 between Juliand hill and Flag gulf, the lowest outcrop on the former will be, 

 approximately, just below that first appealing in the Flag gulf, s<> that our 

 former section is essentially reproduced in the latter, with an upward addition 

 thereto of 250 feet. These consecutive sections give us evidence of a Chemung 

 fauna antedating the Bpwifer disjvmci/tis fauna, and extending through at least 

 400 feet of strata. 



It is necessary to observe that the lower horizons of this essentially 

 homogeneous fauna lie no higher above the Oneonta beds than do some of the 

 smaller, quite distinct faunules which manifest themselves at intervals in the 

 hills bounding the Genegantslet creek, northward to the village of McDonough. 

 But all of the latter are much less firmly characterized by such distinctive 

 Chemung types. In these outcrops are observed such species as the following : 

 Sptrifer mucronatus var. posterns, Grammy sia elliptica, Splienomya subcimeata, 

 Leptodesma Rogersi, Leda diversa, Camarotcechia congregata, Goniophora 

 subrecta, etc., none actually suggesting a Chemung fauna. In this region, 

 however, we are approaching the vanishing western edges of the Oneonta 

 formation. At Greene the evidence is very clear that the Oneonta forma- 

 tion is directly followed by the introduction of a Chemung fauna, and hence 

 occupies the position which I ascribed to it in my preliminary report, replac- 

 ing the upper part of the Portage beds and representing, in this region, the 

 closing stages of Portage time. 



