430 THE CAXADIAN NATURALIST. ' {Yo], ix. 



Taconic system, as first proposed, was later declared by him to 

 consist of an upper division, which he referred to the horizon of 

 the Calciferous sandrock of the New York system, and a lower 

 division, the proper Taconic. In this latter were included a 

 great group of quartzites, limestones, and soft crystalline schists, 

 which have since, by different geologists, been assigned to not 

 less than three distinct horizons in the New York system. The 

 grounds of those contradictory opinions have been supposed 

 Btratigraphical relations, and also the apparent association with the 

 Taconic limestones of organic remains belonging to these various 

 horizons. 



In localities away from the disturbed regions of the xippalachian 

 Valley there exists a series of rocks, occupying the position 

 assigned by Emmons to his Lower Taconic, and agreeing with 

 this in its essential characters. Such a series is found to the 

 north-west of the Appalachian region, a little to the north of 

 Lake Ontario, where it rests upon schists like those of the Green 

 Mountains, and is unconformably overlaid by the Trenton lime- 

 stone and totally distinct from the lower members of the New 

 York system in the adjoining region. Another locality is to the 

 south-east of the Atlantic belt, in southern New Brunswick, 

 where a similar series of several thousand feet of limestone, 

 quartzites, and schists occupies a position inferior to the fossili- 

 I'erous Cambrian (Menevian). In both of these localities the 

 rocks in question correspond closely in volume and in mineralo- 

 gical characters to the Lower Taconic rocks of the Appalachian 

 Valley, with which the speaker believed them to be identical. 



Again Mr. W. 0. Crosby has lately described a similar series 

 in the island of Trinidad, resting on the ancient crystalline 

 rocks, and overlaid unconformably by limestones of Trenton age. 

 We have thus abundant evidence of a great and wide-spread 

 series of rocks, pre- Cambrian in age, and occupying the position 

 assigned by Emmons to the Lower Tiiconic or Taconian system, — 

 which, according to him, extends continuously along the Appa- 

 lachian valley from Vermont to Alabama, and moreover occupies 

 large areas to the south-east of the Blue Ridge, from Virginia 

 to Georgia, constituting, in South Carolina, the Itacolumite series 

 of Lieber. 



Within the vast region occupied by these rocks in the great 

 valley have been found a few small areas of fossiliferous strata, 

 belonging chiefly to the Ordovian (Siluro-Cambrian) or to the 



