214 CALIFORNIA ACADEMY OF SCIENCES. 



generally expanded near its middle but becomes nar- 

 rower posteriorly, reaching back of the opening of the 

 other arm into the genital chamber. Here it makes a 

 bend to the right (plate xvii, fig. 1, pv) and becomes 

 continuous with the oviduct {od). 



The muscles surrounding the genital cavity are con- 

 tinuous over the vagina, forming circular muscles 

 around it which continue throughout its whole length. 

 Outside of these are a few transverse muscles. Grosse 

 states that the muscles begin near the opening. Within 

 the muscles is a structureless membrane which forms 

 the true outer covering of the vagina. Within this is a 

 cellular epithelium lined by a chitinous intima thrown 

 into large folds projecting into the lumen. 



The oviduct (plate xvii, figs. 1-6, od) is very long and 

 somewhat coiled. It varies greatly in different speci- 

 mens, but always runs forward from the anterior end of 

 the vagina as an apparent continuation of it. It is 

 first closely or openly bent upon itself, and then runs 

 again forward to near the anterior end of the vagina, 

 where it bifurcates, each tube running outward and 

 backward, bearing at its end the egg-tubes of the same 

 side. According to the specimen the oviduct may be 

 very narrow or greatly distended. It is formed of the 

 same elements as the vagina except that it lacks the chi- 

 tinous intima. The inner ends of the epithelium cells 

 (plate xvi, fig. 4, ep) project irregularly into the lumen, 

 and the latter is generally almost obliterated by the 

 approximation of the cells, which are much larger than 

 those of the vagina. The muscle layers, on the other 

 hand, are not so thick. 



The egg-tubes are five in number on each side. 

 They arise from the distal ends of the oviducts and 

 have the same structure that they show except that the 



