Clarke— Oneont a,. -Ithaca and Portage Groups. 



58 



This cautionary remark seems in point. The occasional occurrence of 

 species of one fauna in association with those of the other and especially 

 within the province of that other, is not to be construed as conclusive 

 evidence that the species appertains to both faunas alike. Thus, Ma/niicoceras 

 Patersoni is one of the indicial fossils of the western or Naples fauna; it is 

 occasionally found to have wandered eastward among the species of the 

 adjoining Ithaca fauna ; it is thus in the Ithaca fauna, but not of it. The same 

 is true of several other species, and in separating the indicia] features of these 

 two faunas, such facts must be carefully considered. 



In this list are included the species of the Styliola layer (Genundewah 

 limestone) of the Genesee slate, which represent, as shown in other places, 

 the earliest appearance of the Naples fauna. 



Partial list of species constituting the 

 PORTAGE (Ithaca) FAUNA in 

 Chenango and Cortland counties : 



Rhinocaris (?) Cipennis, Clarke. 

 Phacops rana, Green (sp.). 

 Homalonotus DeKayi, Green (sp.). 

 Manticoceras Patersoni, Hall (sp.).* 



Gephyroceras perlatum, Hall (sp.). 



Partial list of species of the normal 

 PORTAGE (Naples) FAUNA in 

 Ontario and Livingston counties: 



Dinichthys Newberryi, Clarke. 

 Acanthodes priscus, Clarke. 

 Palaeoniscus devonicus, Clarke. 

 Conodonts. 



Echinocaris Whitlieldi, Clarke. 

 E (?) Beecheri, Clarke. 

 Manticoceras Patersoni Hall (sp.). 



" " var. styliophilum, nov. 



" " var. contractum, nov. 

 M. simulator, Hall (sp.). 

 M. nodifer, Clarke. 

 M. tardum, nov. 

 M. accelerans, nov. 

 M. oxy, nov. 



Gephyroceras Genundew ah, nov. 

 G. ceryceum, nov. 

 Anabeloceras pseustes, nov. 

 Beloceras iynx; nov. 

 Probeloceras Lutheri, Clarke. 

 Sandbergeroceras syngonum, nov. 



* The names here applied to the cephalopoda are those employed by the writer in an account of this element of the Ponagc 

 fauna, now ready for the press. 



