230 Annals Entomological Society of America [Vol. XI, 



scuto-scutellum demarks the scutellum (si). The posterior 

 edge of the scutellum is produced on either side to a point 

 which connects with the anal margin of the wing. Just anterior 

 to this point, imbedded in the membrane, occurs a small tri- 

 angular plate, the adanal pterale (apt), articulating with the 

 bases of the anal veins. The postscutellum is a narrow piece 

 entirely concealed beneath the edge of the scutellum and fused 

 with the anterior phragma of the metathorax. It is connected 

 with the mesoepimeron by a narrow postalar bridge (Figure 4, 

 poa). This has been termed pleurophragmite, pleurotergite, 

 and postalare by various authors. The term postalare appeals 

 to the present writer, as there is a corresponding prealare in 

 front of the wing. 



Pleuron. Figures 2 and 4. The mesopleuron of the Cicada 

 is decidedly primitive and resembles the condition found in 

 certain Neuroptera. The pleural suture (p) is particularly dis- 

 tinct, extending from the wing base to the articulation of the 

 coxa. The episternum (esj is divided by a suture (a) into an 

 upper and a lower region, called respectively the anepisternum 

 (aes) and the katepisternum (kes). The upper portion has 

 often been wrongly designated as the whole episternum, but. as 

 Crampton, 1914A, 1914B, has shown, the episternum always 

 extends the entire length of the pleural suture. The anepister- 

 num (aes) is partly divided vertically by a cleft running about 

 parallel to and near the pleural suture. In Cryptotympaua 

 epithesia, a large Sumatran Cicadid, and probably in other 

 forms, a median portion (mes), in addition to the upper and 

 lower parts, is marked off on the episternum by sutures. A 

 similar condition is to be observed in certain Neuroptera. 



The katepisternum (kes), the precoxale, or precoxal bridge 

 (pcx), and the sternum are indefinitely fused. Above the 

 episternum at the base of the wing is a free sclerite, the posterior 

 basalare (pba) . Another plate a little in front of and below this 

 sclerite is the anterior basalare (aba), which is only partly 

 separated by a cleft from the episternum. The spiracle of the 

 mesothorax is located anterior to the prealare and is surrounded 

 by a chitinous plate, the peritreme (pt). 



The epimeron (em), like the episternum, is divided into an 

 upper region (aem) and a lower region (kem) b}^ a prolongation 

 (b) of the suture which divides the episternum. These regions 

 liave been designated variously as hyperepimeron or anepimeron 



