52 



Report of the State Geologist. 



for example, in the presence of the Cla&ochonus fauna at various points, the 

 appearance of Spirifer Icevis at Station IX 1 , and its second and final appear- 

 ance at Cowles hill, Greene, strong reappearances of Hamilton types, as citea 

 above, and the relative position of Spirifer mesasfrialis in its first appearance. 



While it is doubtless correct, to a certain degree, and in accordance with 

 the views expressed by Professors Hall and Williams, tb regard the entire 

 fauna present in the strata lying between the Sherburne flags beneath ana 

 the well defined Chemung fauna above, as a transitional expression from the 

 Hamilton to the Chemung fauna, it is evident that this fauna requires a 

 single term, as the expression of its relation to the single geologic horizon to 

 which it pertains. If, therefore, the term "Ithaca" is to be perpetuated in 

 geologic nomenclature, it must be modified slightly as a geologic term, and 

 expanded in its application to the fauna. 



In view of the fact that the local name was unfortunately chosen and that 

 the typical section is through interpenetrating faunas neither of which is at 

 its normal, it would probably be advantageous to our nomenclature if we 

 should follow the example of Professor Hall in abandoning the term in all its 

 applications; such procedure would bring us at once to a ready solution of 

 our difficulties, as excellent terms expressive of the formation and the faunas in 

 their purity are at hand in the counties of Cortland and Chenango. The 

 Otselic river, rising in Madison county and meeting the Tioughnioga at 

 Whitney's Point, transects in an almost north and south line the entire for- 

 mation in its best development, and affords numerous admirable exposures of 

 both rocks and faunas. The term, Otselic group, for the geologic formation, 

 and its equivalent, Otselic fauna; tower Otselic fauna for the earlier mani- 

 festations without Spirifer mesastriaUs and with the Hamilton expression 

 strongly emphasized; the upper Otselic fauna for the later expressions with 

 Spirifer mesastriaUs, would be precise and grateful terms. Eventually such 

 terms will be required, but with proper respect to historic rights, we, for 

 the present, continue to employ the old terms though with a modified 

 meaning. 



It is my desire to enforce, at this point, the far reaching contrast in the 

 western, <>r Naples, and the central, or Ithaca fauna of the Portage epoch, but 

 this is possible only under disadvantages. The Naples fauna is composed to 

 a very considerable degree of unnamed species, many of which can be men- 

 tioned only in paraphrase, and no one lias yet recorded in full the composition 

 of the [thaca fauna. The lists w hich are appended are compiled from my own 

 records w ith the aid of those published by Professors Williams and Prosser. 



