640 WILLIAM A. HASWELL. 



continued as an exceedingly fine tube connecting together the 

 lobes of that organ. 



The above account of the efferent part of the male apparatus 

 differs in certain important respects from the accounts that 

 have been published of the structure of those parts in Pro- 

 rhynchus. The exceptional position of the male aperture is 

 shared with that genus and certain of the Alloiocoela. The 

 form of the penis corresponds^ to some extent, with that of 

 Prorhynchus stagnalis as described and figured by v. 

 Graff.^ The chitinous lamellae of the penis sheath which he 

 describes obviously correspond to the chitinous rods referred 

 to above. But if Hallez's statement be correct, that in Pro- 

 rhynchus stagnalis the sheath is continued back as the 

 wall of the true ejaculatory duct, which encloses an inner 

 duct continuous with the wall of the penis itself and passing 

 back to the '' secretion reservoir/' then there is at least one 

 important point of difference. 



The testis (figs. 1 and 2,te.) is a long narrow body extending 

 from a little behind the posterior end of the pharynx on the 

 left side of the intestine between it and the main trunk of the 

 excretory system to near the posterior end of the body. It is 

 divided into a large number — over a hundred — of small lobes 

 connected together by the efferent duct and its branches. 

 Investing the lobes is a thin layer of connective-tissue fibres. 



The female (fig. 1, ? ) aperture is situated in or near the 

 middle line on the ventral surface. It leads through a short 

 passage lined with ciliated cells into a rounded chamber 

 (vagina) lined with an epithelium, the cells of which are large 

 and similar in general shape to those of the epithelium of the 

 intestine, but much shorter. From this there runs forwards a 

 wide pyriform chamber, which may be provisionally termed 

 uterus (fig. 1, ut.). It has a wall composed of a fibrous layer 

 and a layer of large cells similar to those lining the vagina. 

 From the first-mentioned chamber the oviduct, a wide sinuous 

 tube with a lining of somewhat flattened granular cells, passes 

 backwards and to the right to become continuous with the 

 1 Loc. cit., p. 265, Taf. xv, fig. 19. 



