232 Annals Entomological Society of America [Vol. XI, 



Notutn. Figure 5. The notum of the metathorax is narrow 

 from front to rear. The prescutum (psc) is but a narrow band. 

 The scutum (sc) is narrow at the summit and broadens as it 

 reaches the wings. The scutellum (si) is ill defined at the 

 summit. It is produced laterally into a narrow band bearing 

 the axillary cord, which is continuous with the anal margin of 

 the wing. The postscutellum (psl) is also narrow^ and is joined 

 by the postalare (poa) to the epimeron (em). 



Pleuron. Figure 5. The metathoracic pleuron is divided by 

 a distinct pleural suture (p). The episternum (es) is undivided 

 and is fused ventrally with the precoxale (pcx). The posterior 

 basalare (pba) rests on the anterior basalare (aba), while the 

 latter rests on the episternum (es) ; all are closely united, but the 

 sutures demarking them are distinct. A wide peritreme (pt) 

 joined to the episternum surrounds the spiracle. The epimeron 

 (em) of the female is large and rectangular. In the male a 

 broad lobe (op), called sometimes the operculum, extends back- 

 ward from the epimeron and sternum, forming a cover for the 

 tympanum or sound producing organ. In either case the post- 

 coxale is indistinct. An anterior (asa) and a posterior subalare 

 (psa) support the anal part of the wing as in the mesothorax. 

 The trochantin (tn) is long and narrow in this segment. 



Sternum. Figures 2 and 5. The sternum of the metathorax 

 consists of basisternite (bss. Figure 2; bs, Figure 5) and furca- 

 sternite (fss, Figure 2). The latter region together with the 

 episternum is prolonged posteriorly to cover the tympanum in 

 the male. The meral region (me) of the coxa bears on its 

 posterior side a flattened spine or spur (mc), called by Fieber, 

 1875, the meracanthus. 



MODIFICATIONS IN OTHER HOMOPTEIL\. 



It is difficult to trace the development of the Homoptera 

 along definite directions toward the various modifications 

 which characterize the higher forms. All the families show 

 close relation to each other, but most of them possess striking 

 features not comparable or traceable to features in others. The 

 following are among the more striking modifications occurring 

 throughout the Homoptera. 



Prothorax. Figures 10 and 11. 



The prothorax of Membracids is developed to extreme pro- 

 portions. It covers a good part of the mesothorax and extends 



