NO. 6 GRASSHOPPER ABDOMEN — SNODGRASS 29 



2^"/. Muscles of the spermathecal duct. — The entire length of the 

 spermathecal duct is covered by a muscular sheath consisting of outer 

 longitudinal fibers and inner circular fibers. 



The following muscles of the ninth segment of the male pertain 

 entirely to the phallic organs and tlie ejaculatory duct. It is impossible 

 to discover any identity between them and muscles of the female. 



2y8. Epiphallic muscle of the aedear/us (fig. 25 B, C). — A long 

 muscle lying dorsally in the basal fold of the phallus, attached an- 

 teriorly on the lateral lobe of the epiphallus (h), and posteriorly on 

 the zygoma (s) of the aedeagal apodemes. 



i'/p. Lateral muscle of the aedeagus (fig. 25 B). — A short muscle 

 arising lateroventrally in the base of the aedeagus, inserted dorsally 

 on the lower edge of the lateral plate {m) of the aedeagus. 



280. Muscle of the ventral lobe of the aedeagus (fig. 25 B). — A 

 delicate muscle arising within the base of the aedeagus, inserted dis- 

 tally near the apex of the ventral lobe of the latter. 



281. Lateral dilator of the endophallus (fig. 25 C, E). — A broad 

 sheet of muscle arising dorsally on the aedeagal apodeme (C, Apa), 

 the fibers extending ventrally and anteriorly to the endophallic apo- 

 deme (C, E, w). 



282. Dorsal dilator of the endophallus (fig. 25 F). — A broad flat 

 muscle on the dorsal surface of the endophallic bulb, arising laterally 

 on the inner face of the aedeagal apodeme (Apa), inserted mesally on 

 the dorsal edge {x) of the lateral plate of the endophallus. 



28^. Compressor of the endophallus (fig. 25, E, F. G). — An un- 

 paired transverse muscle uniting the endophallic apodemes (w), the 

 fibers covering the anterior and anteroventral walls of the endophallic 

 bulb (G). This muscle approximates the endophallic plates and dilates 

 the orifice of the ejaculatory sac. 



284. Compressor of the ejaculatory sac (fig. 25 C, E). — A broad 

 sheet of muscle arising internal to 281 (C) on the lateral plate of the 

 endophallus, the fibers converging ventrally to their insertions on the 

 lateral wall of the ejaculatory sac (E, ejs). 



285. Muscles of the ejaculatory duct (fig. 25 E). — A thick sheath 

 of circular fibers surrounds the ejaculatory duct from the entrance of 

 the mucous glands to the beginning of the ejaculatory sac. 



MUSCLES OF THE TENTH SEGMENT 



The muscles of the tenth segment have no evident relation to the 

 muscles of the preceding segments. They comprise muscles to the 

 cerci, the epiproct and the paraprocts, dilators of the rectum, and in the 

 female a transverse intrasegmental muscle. 



