262 



ELEMENTARY STUDIES IN INSECT LIFE 



A. 



B. 



FIG. 199. Side view of thorax, 

 larged three times. 

 A, Mesothorax. 

 a, parapteron. 

 6, episternum. 



c, epimeron. 



d, wing. 



En- 



B, Metathorax 

 6', episternum. 

 c', epimeron. 

 d', wing. 



wings, is the episternum of the mesothorax. ISTote that 

 this part-way surrounds the socket of the leg, and articu- 

 lates with the lateral margin of the sternum beneath. 



Students at this time will 

 carefully distinguish the 

 difference between color 

 markings and sutures 

 proper. (Fig. 199, Z>.) 



Parapteron. Just cepha- 

 lad or in front of the meso- 

 thoracic wing is a very 

 small triangular sclerite, 

 the parapteron. This 

 sclerite is inconspicuous, 

 and not readily discerned. 

 Epimeron. Extending from the base of the front 

 wing to the socket of the mid- 

 dle leg lies the epimeron of 

 the mesothorax. (Fig. 199, c.) 

 Make a drawing of the lat- 

 eral aspect of the mesothorax. 

 Ventral View. Between the 

 nicsothoracic legs, forming 

 the ventral surface of the 

 mesothorax, is a prominent 

 quadrangular sclerite, nearly 

 straight on the front margin, 

 but on the median line of 

 caudal margin there is a 

 well-developed dovetailed structure, making a 

 notch in this segment. (Fig. 200.) 



FIG. 200. Ventral view of thorax. 

 Pro. St., prosternum ; Mesa. St., 

 mesosternum ; Mtta. St., metaster- 

 num. Enlarged about three times. 



broad 



