of Nova Scotia, 139 



the mean time I may merely state that it is most readily charac- 

 terised by the form of the celkiles, -which are very distinctly 

 marked in the manner of Grajptolithus, A portion of a frond is 

 represented in Fig. 2. 



Fig. 2. — Part of frond of Dictyonema Websterij Hall, a, portion magnified. 

 The Dictyonema slates of Beech Hill are of great thickness, but 

 have in their upper part some hard and coarse beds. They are 

 succeeded to the south by a great series of dark coloured coarse 

 slates, often micaceous, and in some places constituting a slate 

 conglomerate, containing small fragments of older slates, and 

 occasionally pebbles of a gray vesicular rock, apparently a 

 trachyte. In some parts of this series there are bands of a coarse 

 laminated magnesian and ferruginous limestone, containing fossils 

 which, though much distorted, are in parts still distinguishable. 

 They consist of joints of crinoids, casts of brachiopodous shells, 

 trilobites and corals. Among the latter are two species of As- 

 trocerium, not distinguishable for A. pyriforme and venustum of 

 the Niagara group, and a Heliolites allied to H. elegans, if not 

 a variety of this species. On the evidence of these fossils and 

 the more obscure remains associated with them. Prof. Ilall 

 regards these beds as equivalents of the Niagara formation of the 

 New York geologists, the Wenlock of Murchison. Their general 

 strike is N. E. and S. W. ; and to the southward, or in the pro- 

 bable direction of the dip, they are succeeded, about six miles from 

 Beech Hill, by granite. They have in general a slaty structure 

 coinciding with the strike but not with the dip of the beds, and 

 this condition is very prevalent throughout this inland metamor- 

 phic district, where also the principal mineral veins usually run 

 with the strike. The beds just described run with S. W. strike 

 for a considerable distance, and are succeeded in ascending order 

 by those next to be described. 



ni. — Devonian. 

 It is probable that Devonian rocks, in a metamorphosed state 



