NO. 8 



INSECT ABDOMEN SNODGRASS 



53 



segment (IX) and the basal plates of the ovipositor (Ovp). This 

 relation is more clearly shown if the dorsum of the abdomen is sepa- 

 rated from the pleurosternal parts (C), the dorso-pleural line (a-a) 

 being theoretically carried out above the bases of the cerci (Cer). 

 It is thus to be seen that the basal plates of the ovipositor (C, iVlf, 

 2Vlf) belong to the pleural area of the abdomen (P), and that, there- 



Sex 



Abdomen of Gryllus assimilis. 



A, lateral view of male abdomen and metathorax, showing groove (a-a) 

 along dorso-pleural line above thoracic subcoxae and limb base, or pleural, 

 region (P) of abdomen. 



B, end of abdomen of female, showing relation of base of ovipositor to eighth 

 and ninth segments. 



C, same part of abdomen separated along dorso-pleural line (a-a). 



fore, they correspond in position, at least, with the subcoxal plates of 

 the thoracic leg bases (A, Sc.v). 



A closer study of the membranous lateral areas of the visceral 

 region of the abdomen (fig. 15 A) shows that the dorso-pleural fold 

 (a-a) on each side is bordered above by an undulating series of slender 

 sclerotizations, and below by a similar series of somewhat thicker 

 sclerotizations. The upper series evidently marks the lower edge of 

 the dorsum (D), and the lower series the upper edge of the pleuro- 



