FAM. MEMBRACID.E i3 



the phytophagous habits of the insects, the usual colors run to greens, yellows and browns. The body 

 colors are generally brown and black. A few tropical species show rather gaudy markings of red, 

 yellow and orange, aiid these colors occasionally appear in the nymphs. The colors in general, even 

 the brighter ones, are permanent, with the exception of the various shades of green, which fade in 

 cabinet specimens. Most colors, except the greens, change but Httle when the specimens are preserved 

 in alcohol. 



The Head. — In its essential parts, the head of the membracid differs little from those of other 

 Homoptera. It varies within the family in size and shape of the sclerites, but shows Httle variation in 

 their location or relative position. 



The position of the head varies decidedly and this has been used as a systematic character in 

 certain subfamiUes (e. g. Buckton igoS). The variation ranges from an angle slightly greater than a 

 right angle with the body, in certain Smiliina, to an almost prone position in many of the CentroUna. 

 In no species does the head project straight forward on a line with the body,and in practically all 

 species, no matter what the position of the head, the beak projects directly backward and lies between 

 the coxae when at rest. 



The compound eyes are large and prominent and are located at the extreme lateral margins of 

 the head. In most cases the thorax is hoUowed out to receive the eyes, and partly covers the upper 

 and outer surfaces. 



Tvvo ocelli are present. These are located on the cephalic margin of the head, and their posi- 

 tion with relation to each other and to the eyes is apparently constant within a species. This offers in 

 some subfamilies, particularly Darmna, a good specific character. The ocelli are always between the 

 eyes and usually on a line with each other; but they may be near together close to the epicranial suture 

 or far apart near the inner margins of the eyes. 



The antennae are located below and slightly in front of the eyes. These organs are very poorly 

 developed, and studies in the biology of the insects seem to indicate that their function is extremely 

 limited. Three basal segments are present, each niore or less cylindrical, with the first segment the 

 shortest. The filament is fine and hairlike and very minutely segmented. From seventy-five to 

 eighty-two segments may be counted in the filaments of the species of the Smiliints, and a slightly 

 smaller number in the other subfamilies. These segments are longer at the base, closely compressed 

 in the center and longest at the extreme tip of the fllament. At the swollen base of the filament are a 

 series of pits, from eight to tvvelve in number, situated on the inner curvature and giving rise to two or 

 more bristle-like seta?. These structures are best seen in certain species of the tribe Telamonini of the 

 subf. Smiliina. The antennas are usually better developed in the nymphs than in the adults. 



The occiput consists of two sclerites more or less distinctly separated from each other, occupying 

 the extreme hind part of the dorsal surface of the head and foi ming caudad the upper boundary of the 

 occipital foramen. This region is covered by the overlapping fiange of the anterior prothorax, which 

 forms with it an articulating surface and is not visible unless the head is separated from the body. The 

 lower ends of the occiput behind are fused with the postgenae belovv them and the suture is very indis- 

 tinct in the adult head. In the nymph, however, the line of demarkation can usually be determined. 

 Apparently these two regions — occiput and postgenae — are intimately connected in the membracid 

 head and are probably closely related as to origin. The ordinar}' lower boundary of the sclerites appears 

 to be the upper line of the eye, but in a few cases the suture has migrated to a point considerably below 

 this line. 



The vertex likewise consists of two sclerites, separated by the epicranial suture, and makes up the 

 largest area of the cephalic part of the head. The sclerites are equal in size and are complements of 

 each other in shape and position. The vertex occupies all that part of the head between the compound 



