GEOGRAPHICAL DISTRIBUTION. J 25 



The extreme range of the thermometer extends from 

 38° below zero, Fahr., to 100° above, making one hun- 

 dred and thirty-eight degrees ; and the mercury often 

 remains below zero for many days together. The sum- 

 mer heat, though never long continued, is excessive. 

 The prevailing rocks west of Lake Superior are primary, 

 the soil is thin and poor, and the vegetation stunted. 

 Operated upon by these causes, the species which pre- 

 vailed in the preceding section become less and less 

 numerous as the secondary region east of Lake Superior 

 runs out farther west, and finally disappear. The genus 

 Vitrina is, however, indigenous to it, and Jlelix inornata, 

 which is believed to reach a more northern as well as a 

 more elevated position than any other species, is also 

 fomid in it. Here appears also the singular little Bul- 

 imus harjpa, which is unknown farther south. This sec- 

 tion is but httle known. 



Section 6. The North-eastern Section. This lies 

 between the St. Lawrence River and the Atlantic Ocean, 

 and comprises the northern parts of New York and Ver- 

 mont, and all New Hampshire and Maine ; the British 

 provinces of New Brunswick and Nova Scotia are also 

 included within it. Its summers are short, and its win- 

 ters long and severe, exhibiting extreme reductions of 

 temperature, but modified by its proximity to the ocean. 

 In Nova Scotia, which is almost insular, the winters are 

 said to be much more mild than in the same parallel of 

 latitude in Canada. In its general character, as affected 

 by climate, the section resembles the precedmg, and 

 though separated from it by a great extent of interme- 



