68 



long, strong hairs. Each paraglossa lies slightly laterad of 

 the distal half of the glossa. The entire ligula arises, not 

 from the cephalic margin of the mentum, but from its inner 

 or dorsal face, and it may be that its parts are not homolo- 

 gous with the terminal lobe (ligula) of the locust's labium, 

 but that one or perhaps both parts are continuous with the 

 lining of the mouth-cavity ; in which case they would be 

 homologous with the hypopharynx of the locust's mouth. 



Make a drawing of the ventral (outer) aspect of the 

 labium. 



PARTS OF THE THORAX. 

 PROTHORAX. 



Dorsal aspect. — The pronotum is not divided into differ- 

 ent sclerites, but appears as a single, firm, convex plate, bear- 

 ing a median impressed line, and, laterad of this line, on 

 each side near the caudal margin, a short, linear depression. 

 At the acute lateral margins, the pronotum is inflexed, 

 extending a little distance ventro-mesad on the ventral 

 (pleural s. str.) aspect of the body. This inflexed portion is 

 often called \.\\e prothoracic epipleura. 



Ventral aspect. — The sternum and the true pleural scle- 

 rites or " side pieces," together form the ventral aspect of 

 the prothorax. 



Stermi?n. — The sternum, constituting the median region of 

 this aspect, is irregularly saddle-shaped, with a caudad-pro- 

 jecting tongue between the coxal cavities. This tongue after 

 reaching the caudal margins of the coxse bends at right 

 angles and projects dorsad, the end expanding slightly into 

 two dorso-laterad projecting points, which meet a ventro- 

 , mesad projecting point of the epimeron on each side, and thus 

 form part of the enclosing, caudal boundaries of the coxal 

 cavities. 



