070 XBW YORK STATE MUSEUM 



«»a8teru Anu'i-ica; but there is abiimlant evidence to show that 

 the species themselves have come into the jjnlf by tlie north- 

 west passaj^e. 



Naples fauna 

 This is the fauna of the Styliola lliiu'stone embedded in 

 llu' \>\;irk (Iciicsre slijiN's and of liic INu-taji^e beds of western 

 New York, ran;,nn;i: nj> lo and lievond llic summil (d* Ihe orij^inal 

 Portaji:e sandstones. The fauna is dislincllv an invader from 

 the northwest.^ It has almost nauj^^ht in connnon with the 

 Hamilton fauna which ]M*eceded it on tin* j^round, but is a con- 

 jreries of oeeanic or^Muisms which toj^^ether eonstitute the zone 

 of M a n t i c o c e r a s i n I u m e s c e n s , well maiked in many 

 liarts of the world but nowhere with a more i»rolitic fauna than 

 here. Eastward cd' Tayuoa lake its inte«i:rity is lost by mergence 

 with the contemiMM-aneous Ithaca fauna. The mij?ration path 

 of this iHdajiic- fauna has been traced toward the northwest 

 throuji:h Manitoba into Siberia, thence throu<,Hi Kussia into 

 Westphalia. Where it was orin^inally autochthonal is not cer- 

 tain; perhaps Westphalia was its home, but in New York,*where 

 its fauna became extensive, it was alien and short-lived. 



Ithaca fauna 



(Contemporaneously with the Naples fauna in western New- 

 York the Ithaca fauna held the tield in central New York ap- 

 I»roximately, except in its latc^st stages, from (^lyuga lake on 

 the west to the Chenango valley on the east. 



The Ithaca fauna is genetically seiiuential to the fauna of 

 the Hamilton epoch. Its species are at tirst identical with 

 those; then variations snperinduc<'d on these specific types man- 

 ifest themselves, and in the event the fauna in its totality is 

 clearly distinct from its ancestor. Hemmed in on the east 

 by the barrier which made the Oneonta waters a lagoon, and 

 <»n the west by the invading Naples fauna, it found favorable 

 o[»portunity for multiplication and variation on ancestral 



'The authors of the preceding paper regard the Naples invasion as from 

 tlie Atlnntic. Tliis is ,in Mssninption inisupiMwtt'd l.y ;iiiy evidence laiown 



to the WlilcC. 



