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sued,—from which it has resulted that we know their habits only in 
the most conspicuous situations, and have not a fair idea of the 
general average of their food. Neither have observations of any kind 
been numerous enough to enable us to detect clearly differences of 
food habit in different species or genera of these families; but, with 
slight occasional exceptions, all Carabide have been classed together 
as essentially carnivorous. The following notes are a contribution 
to a more exact knowledge of this subject: 
The method followed has been that of dissection. The alimentary 
canals of beetles, taken in a great variety of situations, at various 
seasons and at different times of day, have been removed, placed in 
glycerine on microscope slides, and opened with small knives and 
mounted needles, so as to display the contents completely. These 
have been studied with whatever power of the microscope was neces- 
sary, and mounted as microscope slides for permanent preservation 
and repeated examination. 
A few special collections of predaceous beetles were made in situ- 
ations where some particular species of noxious insect was particu- 
larly abundant, with a view to determining to what extent the latter 
was preyed upon by its supposed enemies. 
Those from the orchard infested by canker worms, and those from 
a corn field overrun by chinch bugs, were made by myself; the other 
insects dissected for this report, were partly obtained in the course 
of miscellaneous collecting, and partly secured for me especially for 
the purpose, by one of my entomological assistants, Mr. F. M. Web- 
ster, who kept careful notes of the situations in which the specimens 
were taken, the hour of day when they were captured, and the objects 
upon which it seemed probable that they had lately fed. Examples 
of the latter were frequently bottled, with the specimens, for com- 
parison. 
THe Prepacrous Grounp Bretues (Carabide). 
This large and important family of beetles is distinguished by their 
slender or filiform or slightly tapering antenne, taken in connection 
with their five-jointed tarsi; by the articulated outer lobe of the 
maxille, giving an appearance of six palpi, and by the large egs- 
shaped posterior trochanters. 
The fourth and fifth tarsal jomts are not connate, but the first 
three ventral segments are; and the first ventral segment is divided 
into three parts by the hind coxal cavities. The antenne are eleven-: 
jointed, and inserted at the sides of the head, between the base of 
the mandibles and the eyes. ' 
As their common name imphes, they are found mostly on the 
ground. ‘They never attempt to.escape by flight, but run with 
ereat rapidity. 
My notes upon the food of this family are derived from the dis- 
section and study of one hundred and +wenty-five specimens, repre- 
senting thirty-eight species and twenty genera. Eighty-two specimens 
were collected in miscellaneous situations, twelve were taken in a 
field infested by cabbage-worms, ten in a corn-field overrun by 
