IN EASTERN CANADA. AMI. 175 



rington River, from strata now referred to the Riversdale 

 formation, Sir William Dawson placed them in the Millstone 

 Grit formation, so intimate are their relations to the plants of 

 the Coal Measures; and from my own observations also to 

 the faunas and floras which are now known to immedi- 

 ately underlie the Millstone Grit of certain portions of Nova 

 Scotia. 



The Riversdale formation must now, therefore, both on 

 account of its position in the succession of sediments and especially 

 from the life-zones it holds, be classed as an Bo-Carboniferous 

 formation. This formation clearly underlies that series of 

 marine limestones referable to the Windsor formation, as this 

 has been described and mapped out fully by Sir Wm. Dawson, 

 and more lately and with special care and accuracy by Mr. 

 Hugh Fletcher. 



II. THE MARINE SEDIMENTS. 



In the districts of Nova Scotia under examination, besides, 

 the Eo-Carboniferous formations of Union and Rivesdale, con- 

 sisting of red shales and sandstones and conglomerates, more or 

 less strongly cemented together, together with the series of 

 dark grey coloured, and black or greenish and rusty shales as 

 defined by Mr. Hugh Fletcher, forming a great thickness of 

 sediments, constitute one of the cycles of sedimentation peculiar 

 to the Carboniferous System, there occur certain other strata 

 overlying these unconformably, viz. : the marine limestones 

 and associated gypsum, marls, shales and sandstones. 



These marine limestones, &c., hold abundance of fossil organic 

 remains, as shown on the East Branch of the East River of 

 Pictou at Springville ; at Brookfield ; and Miller's Lime Kiln near 

 the D. A. R. Bridge, Windsor, N. S., where the series is highly 

 fossiliferous and the forms are well preserved. The term, 

 " Windsor Series," is quite applicable to these strata and 

 deserves to be recognized as constituting a typical formation 

 or phase of the Carboniferous system in this portion of 

 Eastern Canada. 



