208 Annals Entomological Society of America [Vol. XIII, 



The anterior view of the prothorax (Fig. 10) shows the 

 parts before mentioned. The prodorsum forms the dorsal rim 

 of the foramen and an articulation with the head. At the two 

 lower angles of the foramen are triangular sclerites,- which have 

 .anterior projections. These are the condyles (end) of Lowne 

 and also articulate with the head. Between the condyles is a 

 rounded somewhat shield-shaped sclerite, which Lowne has 

 termed the sella (s). This articulates with the lower part of 

 the occipital foramen of the head. 



Below the sella and condyles and between the coxa (ex) the 

 prosternum (psn) is seen as a somewhat shield-shaped sclerite, 

 b)ut extends posteriorly to meet the sternopleurite. A study of 

 the pleura of the thorax shows many sclerites and sutures of the 

 •other thoracic segments (Fig. 12). 



Posterior to the propleura and below the praescutum is a 

 large, irregular-shaped sclerite, the largest of the pleural 

 sclerites, which is separated from the posterior portion of the 

 mesopleura by a strong suture, the pleural suture (plsu). This 

 suture, arising from the base of the wing, extends irregularly to 

 the middle coxas. The sclerite formed by this suture is made up 

 of the mesoepisternum fused with part of the sternum and pro- 

 epimeron. The sterno pleural suture (ssu) imperfectly divides 

 this sclerite dorso-ventrally, the dorsal portion being the 

 .anepisternum (ans) and the ventral portion the sternopleurite 

 {stp). In the upper anterior corner of the anepisternum is 

 located the anterior spiracle (spa) (Figs. 10 and 12). Behind 

 the upper portion of the pleural suture is an irregularly pen- 

 tagonal sclerite, which has a short suture starting into it from 

 the dorsal border near the wing base. This suture indicates the 

 fusion of two sclerites, the anterior one being the pleural wing 

 process (pwp) and the posterior one the ptero-pleurite (ptp). 

 Below the ptero-pleurite and behind the lower section of the 

 pleural suture is located another irregular five-sided sclerite 

 which is divided by two faint sutures into three parts. The 

 whole sclerite is known as the mero-pleurite and forms the 

 posterior ventral sclerite of the mesothorax. The posterior 

 dorsal sclerite of the mesothorax is located in front of the 

 halteres, and divided into two portions by a slight transverse 

 suture. This sclerite extends to the anterior portion of the 

 scutellum, and is known as the pleurotergite (ptg). 



