546 VEGETATION OF THE [Ch. XXVI. 



exact parallelism of the New York subdivisions, as above enumerated, 

 with the members of the European Devonian, is very great, so few are 

 the species in common. This difficulty will best be appreciated by 

 consulting the critical essay published by Mr. Hall in 1851, on the 

 writings of European authors on this interesting question.* Indeed 

 we are scarcely as yet able to decide on the parallelism of the principal 

 groups even of the north and south of Scotland, or on the agreement 

 of these again with the Devonian and Rhenish subdivisions. 



Canada. — In Western Canada many of the subdivisions of the New 

 York Devonian system, as above enumerated, from the Chemung to 

 the Oriskany formation, have been recognized by the British survey- 

 ors, and are even traceable continuously, as in the Niagara district, 

 from the one country to the other. 



In Eastern Canada, or in the peninsula of Gaspe, south of the estuary 

 of St. Lawrence, there is a great thickness of sandstone, conglomerate, 

 and shales, referable to the Devonian period, and rich in fossil plants. 

 The conglomerates occur in massive beds, one of them being 156 feet 

 thick, including pebbles of white quartz, black chert, jaspers of various 

 colors, porphyries and limestones, with a base of sandstone. They 

 contain fragments of plants and iish-spines or Ichthyodoruhtes of the 

 genera Onchus and Machceracanihum. Above these beds occur sand- 

 stones and shales of great thickness, some of the sandstones being 

 ripple-marked. Towards the upper part of the whole series a small 

 seam of coal has been observed with carbonaceous shale, measuring 

 together about three inches ; it rests on a bed of clay, in which are the 

 roots of Psilophyton (see fig. 518), while stems and leaflets of the same 

 plant are met with in the shale above the coal, and in the carbonaceous 

 shale associated with it. At several other levels strata much like the 

 fine clays of the Carboniferous period are penetrated vertically by the 

 rootlets of this same Psilophyton.\ 



South Africa. — The researches of Mr. Bain and Mr. Rubidge, at 

 the Cape of Good Hope, have established the existence of a large 

 Lower Devonian formation in that part of the southern hemisphere. 

 Curiously enough, the fauna is strictly representative of that in north- 

 ern regions, even to minute coincidences. The late Daniel Sharpe 

 and Mr. Salter described many species referable to Trilobites (Homa- 

 lonotus and Phacops), Annelids (Tentaculites), Mollusks (Cucullella), 

 and large species of Crinoids allied to Phodocrinus, &c, all of the same 

 genera as those found in Cornwall and Germany. 



Vegetation of the Devonian Period. 



From the works of Goppert, linger, and Bronn, we learn that the 

 fossil plants of the Devonian rocks in Europe resemble generically, 

 with vevy few exceptions, those of the coal-measures, and more ample 



* Report of Foster and Whitney on Geol. of L. Superior, p. 302, Washington, 1851. 

 f Sir W. E. Logan, Report of Geol. Survey of Canada, p. 394, 1863. 



