UY VEltA A. IRWIN -SMITH. 



781 



thick-walled duct, tlie vesicula semirialis (vs.), wliicli runs back- 

 to open with the rectum at the anus. At the junction of the 

 vas deferens with the vesicula seminalis, the wall of the latter 

 is very thick, opaque, and finely granular, and probably func- 

 tions as a gland for secreting a seminal fluid. 'J he lumen of the 

 vesicula seminalis is difficult to make out. In all fixed speci- 

 mens, it is filled with what is probably a coagulated fluid. The 

 sperms are small and rounded, with a very distinct nucleus, but 

 show no trace of the characteristic tail of thp tvpical sperm. 



Figs. 23-24. —CVi. fakatum. 



Fig.23. — Obhque section through middle region of trunk of female, show- 

 ing portion of uterus, and anterior and posterior ovaries; ( x 450). 



Fig.24. — Section through the same worm, a httle further back, showing 

 cellular portion of posterior ovary (^j. or'. ); <sp., sperms in uterus; 

 v., vacuoles in wall of intestine. 



Two, equally long, curved, penial sette, and a small, accessoiy 

 piece lie dorsal to the rectum. The setse are bow-shaped, and 

 have enlarged, proximal ends (Textfig.3, j9.8.). Between the 

 sperm-duct and the ventral body- wall, there is a row of block- 



