87 



Batostoma humile Ulrich. 



Batostoma varium U rich. 



Eridotrypa mutabilis Ulrich. 



Nicholsonella ponderosa Ulrich. 



Phyllodictya frondosa Ulrich. 



Phylloporina sublaxa Ulrich. 



Prasopora insularis Ulr ch. 



Dalmanella gibbosa (Billings). 



Hebertella bellarugosa (Conrad). 



Rafinesquina inquassa Sardeson 



Conradella obliqua Ulrich. 



Maclurea logani Salter. 



Actinoceras bigsbyi (Stokes). 



Gonioceras anceps (Hall). 

 *Eurostomites undatus (Emmons) . 

 *Plectoceras sp. 



Triptoceras sp. 



Pleistocene glaciation. — The Black River strata 

 on Cloche island have been planed down to very flat 

 surfaces, exposing glacial striae over wide areas. Gonioceras 

 anceps, Receptaculites occidentalis and Maclurea logani, 

 fossils abundant in the upper half of these Black River 

 limestones, can be readily identified on the glaciated 

 surfaces. 



Goat Island. 



Trenton (Curdsville). — The lowest Trenton strata 

 exposed along the line of railway, occur near the north- 

 eastern shore of Goat island, and are referred to the Curds- 

 ville division of Kentucky. They contain many of the 

 species found in the underlying Black River limestones, 

 but with the absence of Gonioceras, Receptaculites and 

 Maclurea, and with the presence of a number of crinoids 

 and cystids not seen in the underlying strata. Among 

 these, Carabocrinus vancourtlandi, Billings, is common, and 

 Glyptocrinus ramulosus, Billings, is represented by numerous 

 columns of large size, but by few calices. The crinoids 

 and cystids belong to species characteristic of the lower 

 Trenton at Kirkfield, Ontario, and at Curdsville, Kentucky. 



The species confined to this horizon are given below 

 in list A. Species common to this horizon and to the 

 underlying Black River are given in list B. 



