FAM. MEMBRACID^ 



23 



but their homologies may be questioned. 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, some- 

 times 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 other cases 

 are isolated and seem to have no supporting or bracing function. These hooks have never been used 

 as taxonomic characters, but there seems to be no reason why they should not be so used since they are 

 apparentl}' constant within a species and differ in appearance within a genus. 



The structures mentioned above are diagrammatically indicated in the accompanying text figure : 



2. andJ^^ana/ ye/n^y 



/ ana/ t^/n 



Cubi/a/ ye/n 

 A/fedian ye/n 



_ Rad/a/ we/n 



— Cosfa/ and 

 jubcojfa/ i/e/n 



Z%dllcuy x/er/fe^^ 



/''ax///arif ,sc/erife 

 ■^''axiVaru jc/enfe- 



FiG. 4. — Basal ■tpuoturas of membracid fore wing 



The basal and costal areas of the wing are inclined to be coriaceous, punctured, pubescent or 

 opaque, and these features are commonly used as diagnostic characters. In one subfamily,the Tragopina, 

 the fore wings are so dense nnd coriaceous that the veins are scarceh' distinguishable and this character 

 is generally given as distinctive of the subfamily. 



The hind wing is similar to the fore wing in position and attachment. It rests partly on the 

 dorsocaudal extremity of the metathoracic episternum, and is attached by strong muscles which extend 

 into the body cavity just below the metanotum. The anal lobe is folded under the remainder of the anal 

 area when the insect is at rest. At the base of the anal region is a strong hook, which is generally 

 constant in appearance but the function of which is not evident. The caudal margin of the metanotum 

 shows in some species an overlapping flap which engages the wing when folded. No axillary sclerites 

 have been found in the hind wing. From this fact it might be weli to question the correctness of the 

 interpretation of the structures described in the fore wing as axillaries. There is little doubt that 

 the hind wing in the Membracida is more generalized than the fore wing, and one would naturally expect 

 to find in the more generalized wing the better evidence of primitive structures. The fact that such 

 structures cannot be found would indicate either that the axillaries are not primitive in the family or 

 that the thickenings in the fore wing are not true axillaries. The latter theory is perfectly tenable since 

 their validity as chitinized sclerites may well be doubted. It is true that the fuil complement of 

 axillaries has been recorded for other Hemiptera by Snodgrass (1909), but here again the forms studied 



