1876.] How Cockroaches and Earwigs fold their Wings. 527 
another, constitute the arc. This basal arc is closely attached to 
the lower articulation of the wing with the body in the other 
families of Orthoptera; but in the earwigs one of these veins, 
the second from the attachment (see Figure 41,! which represents 
Fie. 41. 
the wing of Labidura riparia, common in Europe and America) 
extends out nearly to the middle of the wing, emitting on the 
way one or two inferior branches; and, curving upward to the 
front border just beyond the coriaceous part of the wing (from 
which it is separated anteriorly by an incision), forms at this 
point, about the middle of the front border of the wing, the base 
for the attachment of the diverging rays, which sweep around 
_ the entire extent of the wing. The wing may then be said to 
have two bases; one the point of attachment of the whole struc- 
ture to the body ; the other, the pivot in mid-wing, around which 
the extensible major part of the wing plays. The radiating 
veins as well as the independent veins which arise between them, 
show a further peculiarity in having near the middle a consider- 
able expansion, generally accompanied by an equivalent tenuity, 
50 as to make the wing appear delicately coriaceous in a narrow 
““rcuit parallel to the outer border and about midway between 
“and the hinge or pivot in mid-wing. As to the other veins of 
the Wing, their importance is too slight to be worthy of consider- 
ation in this connection ; they occupy but a narrow area border- 
Ing the coriaceous base of the wing and are present only to an 
*xtent ‘sufficient to indicate with certainty that it is the anal 
vein, to which the mass of nervules must be referred. The anom- 
alous Structure of the wing is at once seen on comparing it 
1 Which we owe to the kindness of Mr. Edward Burgess. 
