CHAP. IX MILD AKCTIC CLIMATES 185 



taining a hazel, a plane, and a sequoia, apjDarently identical 

 with a Swiss Miocene species. 



We thus find one well-marked type of vegetation spread 

 from Switzerland and Vienna to North Germany, Scotland, 

 Iceland, Greenland, Alaska, and Spitzbergen, some few of 

 the species even ranging over the extremes of latitude 

 between (Eninghen and Spitzbergen, but the great ma- 

 jority being distinct, and exhibiting decided indications 

 of a decrease of temperature according to latitude, though 

 much less in amount than now exists. Some writers have 

 thought that the great similarity of the floras of Greenland 

 andQj]ninghen is a proof that they were not contemporane- 

 ous, but successive ; and that of Greenland has been sup- 

 posed to be as old as the Eocene. But the arguments yet 

 adduced do not seem to prove such a difference of age, 

 because there is only that amount of specific and generic 

 diversity between the two which might be j^roduced by dis- 

 tance and difference of temperature, under the exceptionally 

 equable climate of the period. We have even now 

 examples of an equally wide range of well-marked types ; 

 as in temperate South America, where many of the genera 

 and some of the species range from the Straits of Magellan 

 to Valparaiso — places differing as much in latitude as Swit- 

 zerland and West Greenland ; and the same may be said 

 of North Australia and Tasmania, where, at a greater lati- 

 tudinal distance apart, closely allied forms of Eucalyptus, 

 Acacia, Casuarina, Stylidium, Goodenia, and many other 

 genera would certainly form a prominent feature in any 

 fossil flora now being preserved. 



Mild Arctic Climates of the Cretaceous Period. — In the 

 Uj^per Cretaceous deposits of Greenland (in a locality not 

 far from those of the Miocene age last described) another 

 remarkable flora has been discovered, agreeing generally 

 with that of Europe and North America of the same geo- 

 logical age. Sixty-five species of plants have been identi- 

 fied, of which there are fifteen ferns, two cycads, eleven 

 coniferse, three monocotyledons, and thirty-four dicotyledons. 

 One of the ferns is a tree-fern with thick stems, which has 

 also been found in the Upper Greensand of England. 

 Among the conifers the giant sequoias are found, and among 



