24 HOMOPTERA 



belonged to the Heteroptera. A study of the alary and pedal apparatus would seem to indicate that the 

 relationship between the Heteroptera and the Homoptera may not be so close in respect to locomotion 

 as in other respects, and the presence of the sclerites in the former suborder need not necessarily 

 presuppose their existence in the latter. 



Aside from the basal region, the wings of the Membracida are usually membranous. It has been 

 noted that in the small subf. Tragopina this is not the case, but this subfamily is very limited in 

 representatives. In general the wing consists of a distinct corium and clavus, the claval suture occurring 

 along the first anal vein. Both pairs of wings are well developed and expanded. Both are charac- 

 terized by having a strongly scalloped margin outlined by the ends of the veins, and in most forms a 

 distinct terminal membrane beyond this margin. The extent of this marginal membrane or limbus 

 is considered a good taxonomic character. The wings may be entirely, partly, or not at all concealed 

 by the pronotum, a variation which has also provetl of value to systematists and on which are based 

 many keys and tables to genera and tribes. 



Other general characters of the wings that are used in taxonomic work are the length as compared 

 with each other, with the abdomen, and with the posterior process, the shape of the extremities, the 

 colors and markings and the venation. Of these, the last-named character is by far the most valuable. 

 This is especially true of the hind wings, which are by far the more constant and apparently the more 

 generalized. Unfortunately the hinii wings are always covered by the fore wings and are usually much 

 shorter than the fore wings, so that their examination necessitates the relaxing of the specimen. 

 Moreover, in many cases both wings are entirely hidden under the pronotum. A more or less super- 

 ficial character of the wing veins, but one which is believed to be of value at least for specific distinction, 

 is the presence of punctures along their courses. In some species each vein is bordered by a double 

 row of such punctures and often by corresponding rows of bristles. 



The Legs. — The legs in the Membracida show some interesting features structurally and are 

 of importance taxonomically. All three pairs of legs are normal in such general points as the number, 

 position, relative size of the segments, and the attachment to the torso. The individual segments, 

 however, are much inclined to variation throughout the family. The legs increase in length from before 

 backward in practically all of the genera, but in a few the first and second pairs are about equal in 

 length. The hind legs are always the longest. It is possible that the relative leg lengths might be of 

 value in systematic diagnosis, but the character would be a very hard one to determine in ordinary 

 mounted material because of the fact that the legs are so often tightly folded against the lower part of 

 the body. In life the front legs usually point forward and the secondand third pairs backward. The 

 front legs, in fact, are attached so closely to the head as to completely hide the mouthparts and the 

 gular regions when the insect is at rest in its natural position. All of the legs, particularly the posterior 

 pair, are very well developed, as would be expected from the jumping habits of the insects. The basal 

 parts are heavy and swoUen and cover most of the ventral surface of the thorax. The legs are much 

 inclined to pubescence and often bear spines. 



The coxae are heavj' and stout. The posterior pair are usually the largest and closest together, 

 and show the greatest tendency toward peculiar development. Each coxa consists of a flattened plate 

 which fiUs up the coxal cavity. and a distal projection to which the trochanter is articulated. This distal 

 projection is often bent at an angle to the other two-thirds of the segment and projects ventrad. 

 Between the body of the coxa and its distal end is found in some cases a constriction or neck. The 

 articulatory surface is generally swollen and apparently distorted. In a large number of species the 

 lateral end of the middle and hind coxae is distinctly cut off, leaving a triangular piece laterad of the 



