ITHACA FAUXA 449 



Pteropoda 



104. Conularia congregata Hall 



This may be a derivative of C cayuga or C. continens, both of 

 the Hamilton group. 



107. Tentaculites spiculus Hall 



This, though smaller, may be a derivative of T. heJhdus of the 

 Hamilton. 



Echinodermata 



The species of crinoids found in the Ithaca all appear for the first time. 

 Their relationships to other species are not known. 



Cephalopoda 



116. Orilioceras hehryx var. cayuga Hall 



A modification of 0. hehryx of the Hamilton group. 



117. demus Hall 



118. OrtJioceras fulgidum Hall ■ 



Confined to the Ithaca beds. 



119. Orthoceras leander Ka.]! 



Also in the Chemung 



120. 0. pacutorJIall 



Probably an immigrant from the Xaples fauna. All these 

 smooth forms are probably derived from Hamilton species, Imt 

 precise relationships can not be determined. 



121. 0. pertextum Hall 



An annulated form with distinctive surface markings; con- 

 fined to the Ithaca ; derivation not known. 



The easteex Ithaca Phase 



The faunal characteristics of the eastern Ithaca beds are obtained from 

 the list of species given by Dr. John M. Clarke for Chenango and Cort- 

 land counties-' and by Prosser for these beds from 78 localities dis- 



John M. Clarke : Annual Report of the State Geologist of New York for 1895. 



