338 LEWIS HENliY GOUGH. 



ventral canal of tlie pore side auJ the cirrus-pouch it becomes 

 distended with spermatozoa, and also slightly convoluted 

 (vesicula seminalis). The cirrus pouch lies ventral or dorsal, 

 anterior or posterior, to the vagina (figs. 4 and 43). The end 

 of the cirrus is bent over and joins the vagina, it does not 

 appear to be introduced into, but fused to the end of the 

 vagina. There is a short and very narrow genital pore into 

 which the vagina opens. The vagina runs straight to dorsal 

 of the nerve and of the testicles ; passing the ventral canal 

 dorsally it widens median of the ventral canal (pore side) to 

 form a receptaculum seminis. From the receptaculum 

 seniinis the canalis seminalis arises, which runs a short dis- 

 tance in the same direction as the axis of receptaculum would 

 if lengthened; then it branches, one branch, the oviduct, 

 turning ventrally towards the ovarium, the othei', the uterine 

 duct, also turning ventrally, leads to the nterus. The ovarium 

 is bean-shaped, or kidney-shaped ; it contains but few eggs. 

 There is no vitelline gland nor shell-gland. Tlie eggs pass 

 through the oviduct into the uterine duct and then into the 

 uterus, fertilisation taking place during the transit. The 

 eggs receive nourishment from certain cells in the ovary and 

 in the uterus (ovarial and uterine nutritive cells, pp. 371, 375). 

 The eggs are finally enclosed in a paruterine organ, which 

 arises within the uterus. Pads of fibrous tissue, lying anterior 

 to the uteri, serve as support to the paruteriue organs, and 

 help to separate the genitalia of adjacent segments. 



The eggs are enclosed in two spherical envelopes; the outer 

 measures 40/<, the inner '2o ft, the embryo h) /.i (fig. 2). 



The Systematic Position of the Genp:ka Stilesia and 



avitellina. 



Fulirmann (1908) placed Sti lesia together with Thysa- 

 nosonia in a new sub-family wliicli he called Thysano- 

 sominie. 



Now that the anatomy of the species of Stilesia and 

 Avitellina are so much better known than they used to be. 



