HETEROMEROUS GROUND -BEETLES. 
123 
ami arc found in rotten wood. The perfect insects are sometimes found 
upon the ground. They are usually of a medium size. The following 
are the principal genera : 
A. Lateral and anterior margins of the front continuous ; body oval ; sides of the breast beneath, often 
striated longitudinally HE LOPS, 24 ap. 
A A. Lateral margin of the front elevated, oblique, and abbreviated. 
B. Body elongated Strong YLIUM, 2. 
BB. Body very convex Heiiacantiia, X. 
Sub-family TENEBKIONIDES. Darkling beetles. 
[Fig. 57,| 
Founded upon the genus Tenebrio, of Linmeus, a name derived from 
the Latin tenebree, meaning darkness, and given to 
these insects on account of their universally black 
color. The family is very extensive, but, as former- 
ly remarked, the great majority of N. American 
species inhabit the western slope of the continent, 
but some species are found in great abundance upon 
the arid plains which extend eastward from the 
base of the Rocky mountains. The typical and most 
common species is the Tenebrio molitor, a plain black 
-Xv“ 0 j,°pupa; R c S i)e^tb;; beetle, six-tenths of an inch in length, whose hard, 
/”ubimn lRr ™iormlnai wax-colored larva is often found upon the floor 
prolcg nt funy ''extended, dU of " T bere grain and meal are stored. Most of these in- 
same alter Riley. sects are found on the ground, but some live under 
the bark of fallen and decaying trees 
principal genera : 
A. Ventral segments entirely horny ; tarsi spinous beneath. 
B. Middle coxae without trochantins 
B B. Middle ooxro with distinct trochantins. 
The following 
are some of the 
.ZOPHERUS. 
C. Thorax transversal, its hind angles prominent and embracing the base of the elytra Asida. 
C C. Thorax heart-shaped, its hind angles not prolonged Pelkcyphokus. 
A. A. Ventral segments 3 and 4 with the hind margin moiubranous. 
D. Elytra embracing widely the sides of the abdomen ; tarsi bristly beneath. .Blaps. Eleodes. 
D D. Elytra not embracing widely the sides of the abdomen. 
E. Eyes divided in two by the margin of the head ; tarsi bristly bonoath Blapstinus. 
E E. Eyes not divided. 
E. Tarsi with a silky golden pubescence beneath Upis. 
F F. Tarsi with coarso pubescence Tenehuio. 
The general remarks made in describing the present tribe, apply par- 
ticularly to the uumerous species of this sub-family. 
Sub-family ULOMIDES. 
This sub family includes a small number of heteromerous beetles, 
which are closely allied to the Tenobrionides in their general characters, 
but differ from them chiefly in their shorter and more or less perfoliate 
antennas, the absence of trochantins in their middle legs, and their 
usually reddish-brown color. The anterior tibiae are more or less dila- 
ted, and sometimes toothed on the outer edge, and the last tarsal joint 
