LOWER SILURIAN FORMATIONS. 



289 



Maclurea, and Glyptocystites are quite sufficient to show 

 that the localities where they have been collected are 

 Lower Silurian, and most probably about the age of the 

 Black Eiver and Chazy limestones.] 



THE BIRD'S-EYE AND TRENTON FORMATIONS. 



The whole of the coast on the north-west side of Lake 

 Winnipeg is represented by Sir John Eichardson to be 

 occupied by the Bird's-eye Limestone.* Near the first and 

 second Eocky Points the strata contain many gigantic 

 orthoceratites which have been described by Mr. Stokes 

 in the Geological Transactions.f 



In Pine Island Lake, there are exposures thirty feet in 

 altitude, containing Orthocerata and Receptaculites Nep- 

 tunii.% The strike is south-west by west, being at right 

 angles to the general direction of the Laurentides. 



THE HUDSON RIVER FORMATION. 



This formation appears in cliffs five-and-twenty feet 

 high at the Stone Fort, Eed Eiver. It is also exposed 

 near the rapids. Most of the forts and churches in the 

 settlements are constructed of stone from this rock. The 



* " As bearing on the resemblance of these (Silurian) quartzose and 

 calcareous rocks to their equivalents in America, I may mention that a 

 recent comparison of several of the American so-called fucoids has enabled 

 Mr. Salter satisfactorily to refer them in many cases to the vertical tubes, 

 or rather filled-up burrows, of large marine worms. He particularly cites 

 the Phytopsis tubulosus of the 1 Calciferous Sand-rock ' of the American 

 geologists ; the celebrated ' Birds' Eyes ' (Phytofms cellulosus) of- the 

 * Birds'-eye Limestone,' and the JButhotrephis succulens of the Trenton 

 group, as being of this nature. The part played by annelides in the older 

 palaeozoic epoch was, we thus know, very conspicuous." — Sir R. I. Murchi- 

 son, Quar. Jour. Geol. Soc, Aug. 1860. 



f Journal of a Boat Voyage through Rupert's Land. 



% Ibid. 



VOL. II. U 



