i6 



INTRODUCTION. 



The upper Ordovician strata of North America occur 

 in formations of so variable a character in different locali- 

 ties that their exact correlation is a matter of difficulty. 

 The practice is now becoming general to embrace the 

 whole series in the term Cincinnatian and to recognize 

 the^following formations : 



Richmond, 



Lorraine, 



Eden, 



Utica, 



Collingwood. 

 The Richmond is a widespread and highly fossiliferous 

 formation, which has been divided into several members 

 in the Cincinnati area. The Lorraine formation is less 

 well defined, particularly in the Streetsville section, but 

 it seems advisable to retain the name rather than to add 

 to the large number of local formational names. 



The Richmond, as exposed in Ontario, consists of a 

 series of marine limestones and shales, and a great thickness 

 of red shales with some green bands and an occasional 

 bed of limestone. The marine type is best exposed in the 

 Manitoulin islands, whence it may be traced with gradually 

 diminishing thickness to the vicinity of Streetsville. The 

 red Richmond shales (Queenston formation) are of great 

 thickness at Niagara and Grimsby, where they are unfos- 

 siliferous and rest directly on the Lorraine. Northward, 

 the formation diminishes in thickness, overlies the marine 

 type and carries fossils characteristic of the Richmond at 

 Collingwood on Georgian bay. 



ANNOTATED GUIDE. 



Miles and 

 Kilometres. 



o m. Toronto. — Alt. 254 ft. (77.4 m.) 



o km. 

 21.7 m. Streetsville Junction. — Alt. 549 ft. (107 



34.7 km. m. A general account of the country along 

 the line of the rai way between Toronto and 

 Streetsville is given in he guide to Excursion 

 B 4 . 



