CO REPORT UNITED STATES ENTOMOLOGICAL COMMISSION. 
this species begins on the coast of Portugal near the 40lh parallel of 
north latitude, and extends from thence northeast through Spain, ris- 
ing obliquely through France to Lake Geneva, and extending from there 
eastward, following approximately the 48th parallel, including Valois, 
Northern Italy, Carinthia, and Hungary, then passing into Southern 
Russia, where it reaches nearly to the 55th parallel. It continues from 
there across the middle of Siberia, passing north of the Chinese bound- 
ary, and terminates in Japan, leaving out the island of Niphon. From 
this point it proceeds southward to the islands of Fidochi to New Zea- 
land and Australia, of which it embraces only the northern portion, and 
passes from thence to the island of Mauritius, and rising to the north 
crosses Africa up to Madeira. But the last part of the limits is more 
hypothetical from want of exact knowledge in reference to the exist- 
ence of the species in the interior of Africa. 
That the immense area embraced within these limits is permanently 
inhabited, even in the broadest sense, fcy P. migratorius, or that its migra- 
tions extend over it we do not believe can be shown. And if we judge 
by this author's paper on the " Destruction of the locusts in Central 
Russia," we do not understand him as reallj' holding this view. 
We will give some reasons for believing that the area over which this 
species roams is less extended than that designated by the boundary 
given. 
That notices of specimens obtained from the extreme portions of this 
extensive area may be found in entomological works and papers we do 
not deny ; but this we do not accept as sufficient to establish the fact 
that the species is to be found in these widely separated sections as 
migratory. That a species may be thus widely distributed we do not 
deny, for several instances of the kind have been clearly proved. But 
aside from the difficulty of distinguishing the migratory from the closely 
allied species of Acridii by single specimens, we are satisfied that the 
evidences in reference to the migratory species within this area con- 
tradict Koppen's conclusion as given by M. Borre. We doubt very 
much whether there is an entomologist in Europe who, without previous 
warning, would at once distinguish between C. spretus and C. atlantis. 
These differences can only be discovered by carefully studying the species 
in their native habitats. It is yet a matter of dispute in Europe whether 
P. migratorius and P. cinerascens are distinct ; and the testimony in 
reference to the migratory character of the latter is so conflicting and 
uncertain that we are unable to come to any satisfactory conclusion on 
the point. Yet Kdppen fails to state whether he considers the two as 
distinct or not. 
Although the descriptions given by travelers are generally considered 
as worthless in determining species, yet we think a careful study of the 
numerous accounts and a proper appbcation of the laws of insect dis- 
tribution, if compared with the more accurate knowledge of these pests 
obtained in recent years, will lead to more correct results than by rely- 
