190 



MEMOIRS OF TEE QUEENSLAND MUSEUM. 



arrangement continues for a little distance, the single dorsal canal of the left side 

 dividing to form two but these eventually rejoin so that there are two and one of 

 these canals respectively, as before. Their further arrangement was not traced in 

 the series, but in sections of segments no sign of any dorsal vessels was recognised. 

 The ventral duct of each side is rather large, and is situated ventrally to the 

 vitelline region. It passes below the outer ends of the sex-ducts. 



3Iale Beproductivc System. — The testes are very numerous and are 

 restricted to two wide lateral fields between the uterus and the vitelline follicles, 

 and extending from the anterior border of the ovary almost to the anterior end 

 of the segment. They are absent above the cirrus sac and vas deferens, which 

 occupy practically the whole of the medulla in that region. The testes lie rather 



Fig. 10. — A mature segment, c.s., cirrus sac ; g.p., genital pore ; ov., ovary ; t., testes 5 

 ut., uterus ; vag., vagina ; vit., zone occupied by the vitelline follicles. 



nearer the dorsal surface of the medulla and are arranged as in fig. 10. In 

 surface view the vesicles are seen to be slightly elongate with the long axis 

 transverse to the segment. Their dorsoventral diameter is between -055 and -06 

 mm. while in surface view they measure about -03 to -05 mm. by -02 to -03 mm. 



The vas deferens is a large and very much coiled tube situated just 

 inwardly from the cirrus sac and overlying both the uterus and vagina. 



