18 BULLETIN 94. 
from the collection of the Colorado Agricultural College and the 
present paper is another attempt to add to the existing knowledge 
of the insect fauna of the State. I hope to follow this paper at no 
distant date with another giving our records upon the remaining 
families of the order Orthoptera. 
It is hoped that the present paper will be found fairly free 
from errors in determinations. There are still a few species of 
Acridiidae not reported because of uncertain identifications and it 
is probable that, in a few instances, I have included under one 
name forms that have been considered distinct but which I could 
not separate except from differences in size or coloration. 
BROODS. 
All of our records point to one conclusion, and that is that’all 
the species here reported are probably single-brooded. 
The number of species reported in this paper are: 
Forficulidse_ 0 
Blattidse_ 5 
Mantidse_ 5 
Phasmidse__ 2 
Acridiidae_ 13B 
Total__ 145 
DISTRIBUTION AND BARRIERS. 
There are almost no cases where sharp lines of limitation in 
this State shut in the distribution of a species. The Continental 
Divide, and the line made by the sudden breaking of the eastern 
plains into the foothills and canons of the eastern slope, come 
nearest to being such barriers; and a few species seem rather close¬ 
ly confined to the area lying above timberline upon the mountain 
ranges. As a general rule, species that occur over the eastern 
plains also occur for some distance into the mountainous region 
but they seldom range higher than 7,000 or 8,000 feet, and many of 
the plains species occur but a very short distance in the hills. On 
the other hand mountain species that are common at 9,000 and 
10,000 feet altitude are seldom found outside the foothills. Some 
species occurring abundantly above timber-line may be found all 
the way to the base of the eastern line of foothills, and Blattella 
germanica , that thrives so well at the sea shore, is equally prolific 
and aggressive in eating houses at mines located above timberline 
in the mountains. There are very few species except those that 
follow in the wake of civilization, that occur upon both the eastern 
and western slopes of the Continental Divide. A few species from 
the south and east have found their way up the Arkansas valley 
into the southeastern portion of the State that we have not found 
elsewhere,and several species occurring in the Platte valley of the 
