38 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Nov. 19, 



In § 2 a veiy different state of things is revealed : there is not a 

 shred of Cambrian schist, nor of its grits and peculiar conglomerates, 

 throughout vast spaces in America, as far as is yet known, embracing 

 many degrees of latitude and longitude, throughout the Arctic Seas, 

 Hudson's Bay, North-east America, with Texas, Nebraska, and 

 Wisconsin. 



We see the same absence of Cambrian schist through vast 

 breadths of Northern Europe, that is, in Scandinavia, the north- 

 west end of Scotland, and in Sardinia. In fact, the larger part of 

 the schistose rocks of examined countries, though apparently Cam- 

 brian, is really Huronian. 



From all these countries, as I have said, schists are either 

 altogether absent or extremely rare. "Where there is an inter- 

 mediate mass of rock, it is a conglomerate supporting the Silurian 

 base, and resting transgressively on the crystalline rocks. To take 

 the following cases : a gneissic conglomerate is seen at and about 

 "Whitehall, on Lake Champlain, New York, in this position ; also on 

 the River San Saba, in Texas ; in Nebraska, among the Black Hills ; 

 on Granite Island, Black Bay, Lake Superior * ; and in the north- 

 west of Scotland and the neighbouring isles. 



The mineral constitution of all these conglomerates is much the 

 same, but wholly dependent on that of the rock below. Thus the 

 red Scottish conglomerate is totally derived from the underlying 

 Laurentian rock, and, though in contact, has no mineral con- 

 nexion with the Silurian above. It is both coarse and fine, and 

 small portions of it are triturated into fine red or purplish sandstone. 



Geol. Soc, passim ; Philosophical Magazine. — Professor Sedgwick and 

 Professor M'Coy. British Palreozoic Rocks and Fossils, 1855. 



Great Britain, &c. — Sir R. I. Murchison. Siluria, 2nd edit. ; Quart. Journ. 

 Geol. Soc, vols, xvi., xvii., et passim. 



Wales, &c. — Prof. A. C. Ramsay. Lectures at Government School of Mines ; 

 Lectures at Royal Institution; Quart. Journ. Geol. Soc. vol. ix. pp. 162, 

 172 ; Geologist, vol. i. p. 171. — W. T. Aveline, Esq. Geol. Survey Sections, 

 sheets 36, 37. — J W. Salter, Esq. Quart. Journ. Geol. Soc. vol. xii. p. 246, 

 and vol. xiii. p. 200. 



Scotland.— G. Tate, Esq.; Geologist, 1860, p. 240.— D. Page, Esq. Brit. Assoc. 

 Rep. 1858.— Professor Harkness. Quart. Journ. Geol. Soc. vol. viii. p r 393 ; 

 vol. xii. p. 239. — Professor J. Nicol. Quart. Journ. Geol. Soc. vol. xiii. 

 p. 17. 



Ireland. — J. B. Jukes, Esq., and Messrs. Wylie and Kinahan. Journ. Dublin 

 Geol. Soc. vol. v. &c. 



France. — MM. Elie de Beaumont et Dufrenoy. Explic. de la Carte Geol. de 

 France, pp. 130, 158, 204, 251.— MM. Lorieux et de Fourcy. Carte Geo- 

 logique de Morbihan. — MM. Dalimier. Bull. Soc. Geol. France, N. S., 

 vol. xviii. p. 664 ; Comptes Rendus, vol. xlvi. p. 636 (Cotentin and Pyre- 

 nees). — MM. de Verneuil, d'Archiac, Rouault, Triger, &c. ; also Siluria, 

 2nd edit. p. 444. — Rozet, Ardennes. 



ALrs. — MM. von Hauer et Fcetterle. Annales des Mines, 5 me ser., vol. viii. p. 130. 



Germany. — Barrande. Syst. Sil. de Boheme; Bull. Soc. Geol. Fr. vol. viii. &c. 

 &c. — Sir R. I. Murchison and Professor J. Morris. Quart. Journ. Geol. Soc. 

 vol. xi. pp. lvi, 412. 



S. America. — D'Orbigny. Cours de Paleontologie, pp. Ill, 169. 



N. America.— Roemer. Bull. Soc. Geol. Fr., N. S., vol. xviii. p. 216.— B. F. 

 Shumard. Bull. Soc. Geol. Fr., N. S., vol. xviii. p. 220. 



* Sir W. E. Logan, Geol. of Canada, 1862, p. 78. 



