3o8 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. Tn 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 cavit}-. 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 

 form'ng the greater part of the dorsal surface of the metathorax. 

 It is limited in front bv a chitinized bar extending between the 

 articulation of the wings and forming the squarish front to the 

 metanotiun. Laterally it is bounded b}' 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 l)road 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 be withdrawn imder the elytron renders the 

 identification of the small veins in that region still more difficult. 



The cosla ( 13) is a short vein l}'ing on the anterior proximal 

 border of the wing and is nowhere coiupletely separate from the 

 vein Iving 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 



