NAPLES FAUNA IN WESTERN NEW YORK, PART 2 383 



raneous with a tremendous development of the brachiopod fauna, which is 

 equivalent in sequence and in composition to that of the Condroz and 

 Famenne sands of Belgium etc. 



3 The geographic subdivision of this integral into (i) the Naples 

 and (2) Chautauqua subprovinces determinates : («) the early arrival of the 

 lower fauna in the Genesee province, its primary occupancy of the entire 

 area, its eventual profuse development at the eastern end of the province 

 till the incoming of the brachiopod fauna from the east ; (b) the subsequent 

 arrival of the organic assemblage which more fully exemplifies the later 

 stages of the Eurasian fauna, stratigraphically sequential to the feeble 

 western development of its predecessor, profuse in its own development in 

 its proper province but unable to penetrate the province of its antecursor, 

 consubstantial and contemporaneous with it during all its own stages but 

 during the later stages only of the antecedent fauna. 



4 The fauna in its entirety shows a subversion of .the facial differen- 

 tials distinguishing its European phases, and species there recognized as 

 successional indexes are here disvalued (Clymenia, En to mis serratos- 

 triata, Chiloceras). On the other hand, entire convergence of faunal 

 differentials is not effected, and certain indexes retain their value in both 

 lower and higher components of the fauna. 



5 In terms of paleontology the fauna as a whole is the Intumescens 

 fauna, for it is permeated throughout, in the development of both of its 

 geographic elements, with goniatites of the type of Manticoceras 

 intumescens and their normal accompaniments. 



6 The uniformity of expression of the fauna as a whole throughout 

 its world-wide manifestation is its most noteworthy character and is without 

 parallel. 



7 By the letting down of the old Mississippian land barrier, which 

 guided the Middle Devonic (Hamilton) fauna from the far south into the 

 Appalachian gulf, the Intumescens fauna entered this region from the 

 northwest, and the proximal part of the path of its migration lies buried 

 beneath Lake Erie. 



