INSECTS. 287 
the poles, are also usually those of the distribution of Insects ; some 
species live even on snow and ice, as a small black insect from the 
order Thysanura, which some years ago (1839) was first discovered 
by Desor on the glacier of Monte Rosa, and after him is named 
Desoria glacialis. 
tung, der Insecten, insbesondere der Kafer, Nov. Act. Acad. Ces. Leop. Car, XVI. 2, 
pp. 805—840. 
