186 THE CANADIAN ENTOMOLOGIST. : 
understood being represented by the corresponding small part of earth 
and the short period of time. 
The aspects from the arctic regions are more impressive than the 
views from the summits of mountains, and the latter renew the remem- 
brance of the former when both have been seen in succession. Visitors 
of mountain-tops may have observed, in a hot, still, misty day, multitudes . 
of insects borne to the summit from the plains below, and filling the air, 
which at other times is free from them, and this is like to the sudden | 
migration of species, from the south to the north, which occurs in Europe 
during some seasons 
In studying the fauna of a mountain, it is most suitable to begin with 
the top, and to trace it downward, where the agencies or forms of life’ 
become successively more numerous and complicated in their mutual 
ese and limitations, all being as wheels which serve to regulate 
the great living mechanism of which they are the parts. In like manner 
in noticing the faunas of the two primary mountains into which the earth 
is divisible, their summits being the poles, and the equator their common 
ase, it is advisable. to begin with the arctic species or with those which 
have ascended to the highest latitudes. The differences in soil, in vege- | 
tation, and in elevation, facilitate or hinder migration and settlement of 
insects, and help to effect the variety of distribution, which is one of the 
chief attractions in the aspects of Nature. 
Leucospis is a genus of Chacidice, and has several peculiarities of 
structure. None of the species occur in abundance, and the very few 
whose economy has been observed are parasites of aculeate Hymenoptera. 
It is well known that the very general colour of the Chalcid tribe is 
metallic, most often coppery or golden green, but Leucospis seems to 
have almost grown out of this hue, though it retains sufficient to indicate 
the transition between it and most of the other Chalcid families. This 
lustre in Leucospis appears chiefly on the face, but in some species it is 
spread more or less over the body. In the single species (L. affinis) 
which inhabits Canada, and whose geographical range extends from 
thence to Texas, it is wholly absent, and there is no trace of it in the 
species inhabiting Arabia, North Africa, and Europe. A few species 
occur in the United States, and the genus is more numerous m Mexico, 
in the West Indies, and in the Amazon region. On the eastern slope; 
this genus inhabits Japan, China, Hindostan, Arabia, the Mediterranean 
region, and more rarely the interior of France, Switzerland, and Germany. 
Oe Ee: LO Ty eee à 7 
