134 THE DEVONIAN AND CARBONIFEROUS. [bull. 80. 



(2) The Portage rocks and faunas are local, the characteristics of each being un- 

 recognizable east of the Cayuga section. 



(3) The typical Portage formations of the Genesee section have quite a different 

 set of species from the rocks occupying the same interval in the Cayuga section, while 

 farther east the same interval is filled by rocks like the Catskill, called the Oneonta 

 sandstones, etc. 



(4) The "Ithaca group" contains & modified Hamilton fauna, which differs from 

 the Chemung fauna in the absence of some of its most characteristic species. 



(5) The modified stages of the Hamilton fauna appearing above the Genesee shale 

 are confined to sections east of the Canandaigua meridian. 



(6) The Catskill deposits of Chenaugo and Otsego Counties are intrinsically not 

 distinguishable from those of the higher stage called Catskill, but appear at a lower 

 position, strati graphically, in the interval occupied by the "Ithaca group" of the 

 Cayuga section, and by the middle part of the Portage group of the Genesee section ; 

 but paleontologically they are immediately preceded by stages of the same general 

 fauna. 



(7) The dominant and most characteristic species of the Chemung fauna appear 

 stratigraphically earliest in the more western sections (D 4 of Girard and Chautauqua). 

 This stage of the fauna appears in the upper part of the Chemung group in the east- 

 ern sections; and in the extreme part of the area this stage of the fauna is all that 

 appears, and it is there represented by only a few specimens in the very upper strata 

 just before the final incursion of the Catskill deposits. 1 



• Op. cit., p. 234. 



