21 



margin of the mesosternum is nearly straight ; the caudal 

 margin, deeply notched by a large, nearly square incision. 



Caudad of the mesosternum there is a large sclerite, the 

 mesal part of which is prolonged cephalad so as to accurately 

 fit the notch in the caudal border of the mesosternum ; this 

 is the sternum of the metathorax or metasternum . 



The caudal border of the metasternum is also notched, and 

 the first abdominal segment is dove-tailed into it. 



Make a drawing of these parts. 



Lateral Parts (Episterna, Epimera, and Paraptera). 

 — Examine one side of the second and third thoracic seg- 

 ments. Note that it is chiefly composed of four large 

 sclerites, which extend from the fossae of the legs dorso- 

 cephalad. These sclerites are named as follows : — 



Episternum of the mesothorax. — The first or cephalic of 

 these four sclerites is the episternum of the mesothorax. The 

 sutures between the episterna and the mesosternum are only 

 faintly indicated in this species. 



Epimeron of the mesothorax . — This is the second of this 

 series of sclerites. 



Episternum of the metathorax. — This is the third of this 

 series of sclerites ;' it is the one which bears the oblique 

 yellow band characteristic of this species. 



Epimeron of the metathorax . — This is the caudal member 

 of this series of sclerites. 



Iu addition to the four large sclerites just described, ob- 

 serve the following named parts : — 



Parapteron of the mesothorax. — Articulated to the dorsal 

 extremity of the episternum of the mesothorax and cephalad 

 of the base of the first wing is a small, inconspicuous, tri- 

 angular sclerite ; this is the pai'apteron of the mesothorax. 



NOTE. — This sclerite can be seen more easily in the Carolina locust, 

 Dissosteira Carolina, a specimen of which will be shown the student 

 on request. 



Parapteron of the metathorax . — Articulated to the dorsal 



