3°8 
The Ohio Naturalist. 
[Vol. Ill, No. 1 , 
is connected with an articular cartilage. On its anterior face it 
bears a circular depression limited internally by a drum-like mem- 
brane. In the body this drum-like membrane is borne on the 
small end of a funnel-shaped piece whose large end extends 
freely into the body cavity. This cone furnishes attachment for 
muscles. Between this sclerite and the end of the prescutum lies 
a circular chitinized area. The scutellum (6) is a large sclerite 
forming the greater part of the dorsal surface of the metathorax. 
It is limited in front by a chitinized bar extending between the 
articulation of the wings and forming the squarish front to the 
metanotum. Laterally it is bounded by a membrane lying below 
and behind the articulation of the wing with the dorsal surface 
of the epimeron. The postscutellum (7) is not well separated 
from the scutellum except at its lateral margins. Posteriorly the 
scutellum is fused with the postscutellum. 
The boundaries of the postscutellum (7) are very difficult 
to make out. In the median line it is a very narrow bar lying 
between the posterior ends of the median rectangular area of the 
scutellum. This narrow bar fades out as it passes to the side of 
the body, but again becomes chitinized and enlarging forms an 
articulation with the median dorsally projecting bar of the epi- 
sternum. Its boundaries are posteriorly the thin membrane of 
the first abdomnial segment, laterally the meta-sternum, and an- 
teriorly it is fused with the scutellum. 
On the posterior border is a thin membrane stretching from 
the second abdomnial spiracle of one side to that of the other. It 
is about as broad as an abdomnial tergum and probably belongs 
to the first abdominal segment. It appears to be simply a broad- 
ened articular membrane, but may include a portion of the post- 
scutellum. 
THE WING. 
The articular membranes at the base of the wings bear sev- 
eral small sclerites which can be located more easily after the wing 
veins have been described. In identifying the wing veins the 
wings should be extended at right angles to the body. The mar- 
gin which lies anteriorly when the wing is extended is called the 
anterior margin and the hinder border the posterior or anal mar- 
gin. The homology of the wing veins is somewhat doubtful and 
the transverse folding of the hinder third of the wing in beetles 
to enable the wing to he withdrawn under the elytron renders the 
identification of the small veins in that region still more difficult. 
The costa (13) is a short vein lying on the anterior proximal 
border of the wing and is nowhere completely separate from the 
vein lying next to it except for a short distance at about one-fourth 
the distance from the proximal end of the wing to the tip. Here 
