6o 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 89 



Strongly sclerotized throughout, and each is strengthened by a high 

 internal ridge. The ventral valvulae are membranous and flexible on 

 their mesal surfaces, and the inner wall of each is thrown into a longi- 

 tudinal fold. 



The muscles of the ovipositor.— The musculature of the cricket's 

 ovipositor is strongly developed, but is not particularly complex. It 

 includes the ventral muscles of the seventh abdominal segment, and 

 the principal lateral and ventral muscles of the eighth and ninth seg- 



VIII T IXT XT 



VllStn Odl Ode VlllStn 2VI 



iVl 



Fig. 18. — Inner view of right half of genital and postgenital segments of 

 Gryllus assimilis. 



Note genital chamber (GC) at base of ovipositor above eighth sternum 

 (VlllStn), with opening of median oviduct (Ode) anteriorly, and opening of 

 spermathecal duct (SpfD) through a spoutlike process (u) in a dorsal pouch 

 (0 of genital chamlaer. 



ments. The muscles attached on, or associated with, the ovipositor 

 are the following, indicated by arable numerals on figures ly and 19 A. 

 I. Retractors of the ovipositor (fig. 19 A). — Origin anteriorly on 

 anterior apodemes of seventh sternum; insertion posteriorly on an- 

 terior extremities of first valvifers (fig. 17 A, E, F, H). These 

 muscles of the ovipositor fall directly in line with the internal ventrals 

 of the pregenital segments anterior to the seventh (fig. 19 A, vi), 

 and are clearly the corresponding muscles of the seventh segment, 

 though here attached posteriorly on the valvifers of the eighth seg- 

 ment instead of on the eighth sternum. 



