April 29, 1875] 



NA TURE 



509 



opinion Mr. Carruthers also exiiressed in reference to the 

 plant both of the Irish and Bear Island deposits.* 



In Eastern America the Lower Carboniferous Coal- 

 measures (Calciferous Sandstone of Scotland) lie uncon- 

 formably on the Devonian, which contains different 

 fossils ; but in Ohio a transition between the Devonian 

 and Carboniferous flora takes place, according to Prin- 

 cipal Dawson, at the base of the latter,+ and he suggests 

 a similar blending in Bear Island. 



Prof. Meek has shown that the rock exposures of 

 the Mackenzie River between Clearwater River and 

 the Arctic Ocean are of Devonian age, and correspond 

 to the Hamilton formation and Genesee slate of the 

 United States. The slates contain brine springs and 

 petroleum, and it is through that they extend in a north 

 westerly direction from Rock Island, Illinois, to the Arctic 

 Sea, a distance of 2,500 geographical miles, the fossils 

 being identical on each end of the tract, proving how little 

 the paljeozoic marine life was influenced by climate. From 

 the Mackenzie slates many new corals and brachiopods 

 were obtained, also a cephalopod, Gyoceras Logdni, col- 

 lected by the late Mr. R. Kennicott.J It is therefore in 

 the highest degree probable that the coal-bearing beds of 

 Parry and Melville Islands belong to a continuation of 

 these beds, and are referable to the "Ursa Stage" of Heer, 

 whether that slate is the top of the Devonian or the bottom 

 of the Carboniferous ; and from the fact that not a single 

 species of the Bear Island flora exists in the Upper 

 Devonian Cypris shales of Saalfeld in Thuringia, Prof 

 Heer believes that the Ursa Stage is Lower Carboni- 

 ferous. In Bear Island it is characterised by Colamites 

 radiatus, Lepidcdeiidron VeltJieitniann>ii, Kjiorria acicii- 

 laris, Stig7iiaria Jicoides, all of which are found in the 

 Yellow Sandstone of Kiltorkan ; and considering the per- 

 sistence of freshwater genera, it is not remarkable that 

 some genera of fish that occur in Old Red of Scotland 

 still lived on in these Kiltorkan sandstones. Should, 

 however, fish remains be found in the strata lying in 

 synclinal hollows of the Silurian rocks of the Arctic 

 regions, their specific determination and that of the asso- 

 ciated forms, may be expected to throw much light on the 

 vexed question of the line of demarcation between Devo- 

 nian and Carboniferous. The presence of Kiwrria acicu- 

 laris in the Melville Island flora is a link between the flora 

 of the South of Ireland and that of Bear Island ; the latter 

 is undoubtedly an outlier of the Russian Lower Carboni- 

 ferous coal tract. Looking to the number of species in 

 this flora, which can be traced in the northern hemisphere, 

 both in the Old and New World, from 47° to 74° and 76° 

 north lat., and to the fact that it is the first rich land 

 flora in the earth's history, there is evidence that a wide- 

 spread continent occupied much of the Arctic as well as 

 of the temperate zone, over which ran large rivers tenanted 

 by the freshwater mussel {Anodontd) and Neuropterous 

 insects. 



The subsidence which brought in the deposition of the 

 Mountain Limestone and the existence of extensive coral 

 reefs equally affected the Arctic zones, and these forma- 

 tions occur both in Spitzbergen and Bear Island, as in 

 the islands of the Arctic Archipelago. Equally also is the 

 return of continental conditions expressed by the Euro- 

 pean Millstone Grit, represented in the Arctic zone by the 

 siliceous schists of Bear Island. During this period many 

 plants of the Ursa Stage still lived in Europe, proving 

 that islands covered with the old flora existed through- 

 out the whole era occupied by the deposition of the 

 Mountain Limestone. And it is worthy of note, as Prof. 

 Heer has pointed out, that the leaves of the evergreen 

 tree Lepidodendra, and the large fronds of Cardiopteris 

 frondosa, are as fully developed as those from the South 

 of Ireland and the Vosges ; and it is clear that the climate 

 of these Arctic regions must have been far warmer than 



* Geol. Mag., vol. vli. p. 580. 



t Quar. Jour. Geol. See, vol. xxix. p. 245. 



t Trans. Chicago Acad, of Science, vol. i. (Chicago, i863.) 



at present, even if the darkness of the long winter nights 

 were the same as now.* 



Spitzbergen.— l-a. the Klaas Billen Bay of the Eis 

 Fjord, Wilander and Nathorst discovered the Ursa Stage 

 in 1S70; overlying it are the Miocene beds which have 

 yielded so rich a flora and fauna to various expeditions 

 which have visited the island. In the black shales of 

 Cape Staratschin, Sequoia Nordcnskj'oldi and Taxo- 

 dium disticJuan are the most characteristic trees. At 

 King's Bay, a Lime {Tilia Malmgreni), a Juniper, an 

 Arborvita; {Thuites Eh!-ensvjaerdi)—ma.ny of the species 

 occur in West Greenland— and two, Taxodium distichum 

 and Papains aretica, were found by Lieut. Payer, of the 

 German Exhibition, in the fossiliferous marls of the 

 Germania Mountains, in Sabine Island, East Greenland, 

 also. At the present time, firs and poplars grow in an 

 area 15° further north than plane-trees ; so that, assuming 

 the former to have reached their northern limit in Spitz- 

 bergen in lat. 79°, the oaks must have grown, provided 

 there was land, as far north as the pole.f 



The so-called wooa-hilh discovered in 1806 by Siro- 

 watskoi on the south coast of the island of New Siberia, 

 stated by VVrangelJ to consist, according to Henenstrom, 

 of horizontal beds of sandstone, alternating with vertical 

 bituminous trunks of trees, forming a hill 180 feet in 

 height, are no doubt part of the great Miocene deposit 

 which stretches from Vancouver's Island through Northern 

 Asia into Europe. The evidence of the former continuity 

 of land is borne out by the presence in Greenland of 

 species of the Japanese genera Glyptostrobus and Thii- 

 Jopsis, which last, T. Europceits, occurs in Europe, in 

 Amber and at Armissan (Narbone) ; associated with it 

 are American forms, which, as pointed out by Prof. 

 Goppert (Geol. Trans. 1845), chiefly characterise the 

 flora associated with the Amber pines of the south- 

 eastern part of what is now the Baltic. 



An examination of the fauna and flora of the Miocene 

 rocks of Europe and Asia indicates a continental period 

 of long duration, which experienced at its commence- 

 ment a tropical climate, gradually becoming more tem- 

 perate as time elapsed. 



In the Upper Miocene beds of ffiningen, North Ameri- 

 can types still live, and are more numerous than in the 

 later Italian Pliocene flora : amongst them is a vine, four 

 palms of the American type, ^rt^j/, planes of American type, 

 and conifers Sequoia and Taxodium. The palms, whether 

 of the European or American type {Chanuerops and 

 Sabal), and other exotic forms, are found to be absent in 

 the Miocenes of the northern area, proving that the 

 climate became cooler in advancing northwards, as at the 

 present time ; for through the enormous expanse of conti- 

 nental land the cHmate was much more equable than at 

 present. There is therefore no reason to believe, from 

 the absence of these plants, and of bones of long-armed 

 apes present in the Miocene of Central Europe, that the 

 Lower Miocene is absent in the Arctic zone ; and from 

 the detennination by Prof. Heer, of Cretaceous forms in 

 the Greenland deposits, it is probable that the continental 

 conditions expressed by the Miocene of Europe and India 

 had commenced in these polar regions as early as Creta- 

 ceous times. Should further discoveries of freshwater Cre- 

 taceous and Miocene deposits lying in the hoUows of the 

 older rocks be found in the northern lands visited by the 

 British Arctic Expedition, it will be of great interest to 

 see how far southern species die out in advancing to the 

 present pole, and what minimum of cold the surviving 

 species appear to indicate. C. E. De Range 



« Prof. Ramsay has directed my attention to Mr. CroU's recent work, 

 "Climate and Time," in which the occurrence of Carboniferous and 

 Miocene species in the Arctic zone is adduced : 

 glacial penods " in these regions. 



t Heer: "Miocene baltische Flo 

 " Flora Fossilis Aretica," vols, i.-iii. 

 lande." Zurich ; Fr. Schulthess, 1867. ... „ „ .>, : 



1 " Reise langs der Nordkuste von Sibenen in den Jiihren, 1830-24. «»■ '• 



vidence of "warm inter- 



" " Fossil Flora von Alaska," 1869 ; 

 ■ LTeber die Fossile Flora der Polar 



