30 THE EEPORT OF THE No. 36 



California and Mexico divided into the same zones as the Atlantic State, in spite 

 of vast and important differences in their fauna and flora. In regard to tempera- 

 ture, these zones are comparable in the east and west, but in little else. They 

 would be more properly regarded as homologous subdivisions of quite different 

 zoogeographical provinces. For the purpose of our catalogue, however, in which 

 we indicate the distribution of species by reference to political divisions, as well 

 as to faunal zones, the map is a convenient one and probably better suited to the 

 purpose than any other map as yet published. 



It may, therefore, be of interest to examine the map for a little while and 

 consider the characteristics of the various zones. 



The continent of North America is seen to be divided into two main regions, 

 a northern or Boreal Eegion and a southern or Austral Eegion. The Boreal Region 

 includes the greater part of Canada as well as the northern parts of Europe and 

 Asia, and gives off southern extensions along the mountains on both sides of the 

 United States; the Austral Eegion occupies the greater part of the United States, 

 part of Mexico, and a small part of Canada. Part of the Tropical Eegion is also 

 included on the map, embracing Central America, the West Indies, and parts of 

 Southern Mexico and Southern Florida. 



Tlie Boreal Eegion m North America is divided into three zones : the Arctic, 

 Hudsonian and Canalian Zones. The Arctic Zone is the region north of the limit 

 of trees, including the Barren Grounds or Tundra of North America and Siberia. 

 It is also represented upon the mountains farther south, wherever tliese are ele- 

 vated above the tree-line. 



The plants and animals of this region, particularly of the truly arctic por- 

 tions, are largely circumpolar, or represented by very nearly allied species in the 

 northern parte of Europe and Asia. 



Tliis is due to the free communication that '-formerly existed between these 

 regions by means of the land-bridges already mentione^d. The mammalian fauna 

 Includes a number of species peculiar to this zone, such as the polar and barren- 

 ground bears, musk ox, barren-ground caribou, arctic fox, arctic hare, lemming, 

 etc. Not much is known of the insects, but mention may be made of the satyrid 

 butterflies of the genera Oeneis and Erebia, the dwarf fritillaries of the genus 

 Brenthis, certain species of Colias, the noctuid moths of the genus Anarta and the 

 grasshopper Melanoplus horealis, a near relative of our common red-legged grass- 

 hopper. There are also some charteristic beetles, besides many species of various 

 orders which also occur farther south. 



South of the Arctic Zone is an immense belt of coniferous trees, stretching 

 obliquely across the continent from Nova Scotia, Newfoundland and Labrador to 

 the Northern parts of the Great Lakes and Hudson Bay, and thence northward 

 of the Great Plains to the Pacific Coast, extending north-westwardly to the Mac- 

 kenzie Eiver Basin and southwardly into the north-western United States, where 

 it is continued along the mountains as a series of irregular, more or less broken 

 areas. It is also continued soutliwardly along the Appalachians to North Carolina. 

 This great forest region comprises the other two faunal zones of the Boreal Eegion, 

 viz., the Hudsonian and Canadian Zones. 



The Hudsonian Zone is a region of more or less scattered and stunted trees, 



occupying the northern part of the Boreal Eegion. It is a transitional region 



between the treeless Arctic Zone and the densely forested belt south of it, which 



constitutes the Canadian Zone. Except towards its southern boundary and in its 



^ mountainous western portions, this forest belt is composed of only eis-ht species of 



