212 REPORT — 1855. 



uniform horizon of Upper Silurian limestone stretched from near the entrance of 

 Barrow's Straits to Melville Island northwards as far as those expeditions reached, 

 and evidently very far to the south along Prince Regent's Inlet. These collections, 

 brought home by the officers and medical gentlemen from various points, showed so 

 many fossils referable to the same types as our own Dudley limestone, and so entire 

 an absence of characteristic Lower Silurian ones, that there need be no hesitation in 

 referring the whole of the limestones, in a general way, to the Wenlock group. 



The common fossils are RhynchoiieUa Phoca, Orthoceras and Alurchisonia ; and 

 there are several species identical with European ones ; e. g. Pentamerus conchidium ; 

 a. trilobite {EncrinuruslcBvis) ; the chain-coral ; Favosifes.polymorpha, &cc. The type 

 of the numerous corals is, however, rather American than European, Favistella and 

 Columnaria being present, — the former abundant. 



The limitation of these strata to the Upper Silurian period is an independent 

 confirmation of the inference drawn by our able friend Mr. Logan as to the age of 

 the lowest rocks he was able to find north of the great Lawrentine chain. These 

 strata, which were certainly shore accumulations, contained in plenty the fossils of 

 the Clinton group (Pentamerus oblongus, Atrypa hemisphmrica, &c., with large spe- 

 cies of Orthoceras, known in North America as Upper Silurian forms). Similar spe- 

 cies of Orthoceras were found far to the west in lat. 02° by Sir John Richardson, 

 and Upper Silurian fossils have been brought by Mr. Isbister from localities 

 nearer to Hudson's Bay. So that the evidence, as far as yet collected, all points 

 the same way, viz. that a wide extent of Polar or circumpolar land existed, during 

 Lower Silurian times, north of this great ridge, which land, at the commencement 

 of the Upper Silurian period, was depressed, covered by sea, and peopled by Mol- 

 lusca and Radiata like those of our own latitudes, many species being identical. 



That this depression continued during the Devonian sera, we have less proof, 

 though it may be inferred from the character of some of the shells collected on the 

 Slave Lake by Richardson, and, as will be presently mentioned, from some of those 

 brought from the furthest point examined by Sir E. Belcher. 



One of the great points, however, established for us by the researches of the 

 last-named officer and his associates, is the existence of a considerable marine Car- 

 boniferous formation in the highest latitudes explored. 



The age of the coal plants of Melville Island was not doubtful after the statements 

 of Drs. Lindley and Buckland ; but it is satisfactory that Capt. M'Clintock should 

 have found in that island, a degree further north than the coal, shells distinctly 

 comparable with those of our own mountain limestone. The Rev. Prof. Haughton 

 has recognized two British species among them ; they are from lat. 70°. Winter 

 Harbour is 75°. 



In skirting the newly discovered coast-line of Albert Land, in lat. 78°, Capt. 

 Belcher found the shore, especially at a place called Depot Point, strewn with blocks 

 of a w'hitish-gray limestone, mixed with some redder fragments, all full of beauti- 

 fully preserved fossils. Tliese he has placed in the Museum of Practical Geology. 

 They prove to be all truly carboniferous types : corals of the genera Clisiophyllum, 

 Zaphrentis, Lithostrotion, Stylastrma and Michelinia ; Brachiopod shells, Producti 

 and Spirifers, with Fenestella, and a new foraminiferous shell of a peculiarly carbo- 

 niferous character, viz. a large species of Fusulina. 



This Fusulina, F. hyperborea, is five times as large as the common Russian species, 

 and is constricted in the middle. It is a most interesting example of the concurrence 

 of similar organic forms with like geological periods. The little Fusulina of Moscow 

 is no bigger than a grain of wheat, but occurs in myriads. A still smaller, rounder 

 species is characteristic of the mountain limestone in Asia Minor; and here, in the 

 Polar circle, another species, gigantic in comparison, occupies the same place, and 

 keeps up the facies of the carboniferous fauna. 



The corals, with one or two exceptions, are not known European species, — a fact 

 in harmony with the previous investigations of Edwards and Hairae. Stylastrcea 

 inconferta of Lonsdale is not, however, rare, and was first described from Russia. 



The Brachiopods, as usual, are the cosmopolite forms. We cannot distinguish 

 the two species of Producti, P. semireticulatus and P. Cora, from English fossils. 

 And when it is remembered that these are found, wherever the Carboniferous rocks 

 have been examined, from India to the Icy Sea, in South America, and one of them 



