328 W. D. FUNKHOUSER 



The position of the fore wing is shown in Plate xxxiv, 8. The principal 

 point of attachment is a long, curved, partly chitinized cord, fused along 

 the costal and the middle part of the wing base (the cephalo- ventral margin 

 when in the normal position) and extending between the notum and the 

 episternum into the body cavity, where it is connected with the wing 

 muscles. This cord supports and probably directs the movement of 

 that part of the wing which accommodates the bases of the costal, sub- 

 costal, radial, median, and cubital veins. It is rather sharply set off, 

 however, from the tissue of the wing proper by a deep constriction. When 

 the wing is separated from the body it usually breaks along this line. The 

 extreme cephalic costal angle is supported by the dorsal margin of the 

 mesothoracic episternum. When at rest and folded against the body, 

 the basal fifth or sixth of the costal margin is supported by the metathoracic 

 episternum, which is hollowed out to receive it. This deep groove in the 

 episternum of the following segment (Plate xxxiv, 9) is indeed very 

 characteristic of the family. 



Results from the study of chitinized parts of the wing base are most 

 unsatisfactory. The tissue of this region, when treated in the usual manner 

 in caustic potash, is generally completely broken down and shows no 

 evidence of impregnation. It is doubtful whether any true sclerites are 

 present, but occasionally slight thickenings of irregular shape are noted 

 which may represent such structures. When visible, these are indefinite 

 in outline, but they may be represented by the shaded areas in Plate 

 XXXIV, 10. They are here tentatively indicated as the first, second, 

 and third axillary sclerites, but their homologies may well be questioned. 

 In fact, histological studies would seem to indicate that the entire region 

 is normally composed of muscular and connective tissue. No evidence of 

 the fourth axillary sclerite has been found. This, however, is not sur- 

 prising, since it has been shown that this sclerite is present only in a 

 limited number of insect orders (Snodgrass, 1909:543). The cephalic 

 costal angle is swollen into a protuberance, or tooth, which is probably 

 homologous with the tegula of other insects. It is usually pubescent, 

 if not actually hairy, but is not chitinized. The basal region of the fore 

 wing is much given to the development of barbs, or hooks, which in some 

 cases interlock with one another or with the notum and in some cases arc 

 isolated and seem to have no supporting or bracing function (Plate xxxiv, 

 12). These hooks have never been used as taxonomic characters, ])ut there 



