CHAP. IX.] 



MILD ARCTIC CLIMATES. 



179 



Straits of Magellan to Valparaiso — places differing as much in 

 latitude as Switzerland and West Greenland ; and the same may- 

 be said of North Australia and Tasmania, where, at a greater 

 latitudinal 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 Upper 

 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 geological age. Sixty-five species 

 of plants have been identified, 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 the dicotyledons the genera Populus, Myrica, Ficus, 

 Sassafras, Andromeda Diospyros, Myrsine, Panax, as well as 

 magnolias, myrtles, and leguminosse. Several of these groups 

 occur also in the much richer deposits of the same age in North 

 America and Central Europe ; but all of them evidently afford 

 guch fragmentary records of the actual flora of the period, that 

 it is impossible to say that any genus found in one locality was 

 absent from the other merely because it has not yet been found 

 there. On the whole, there seems to be less difference between 

 the floras of Arctic and temperate latitudes in Upper Cretaceous 

 than in Miocene times. 



In the same locality in Greenland (70° 33' N. Lat. and 52" 

 W. Long.), and also in Spitzbergen, a more ancient flora, of Lower 

 Cretaceous age, has been found ; but it differs widely from the 

 other in the great abundance of cycads and conifers and the 

 scarcity of exogens, which latter are represented by a single 

 poplar. Of the thirty-eight ferns, fifteen belong to the genus 

 Gleichenia now almost entirely tropical. There are four genera 

 of cycads, and three extinct genera of conifers, besides Glyptos- 

 trobus and Torreya now found only in China and California, six 

 species of true pines, and five of the genus Sequoia one of which 



