A Turbellarian Worm. 41 



animal with reflected light. Frequently the oviducts may 

 be traced as a pair of straight lines leading directly back- 

 wards from the ovaries. The testes appear as rounded 

 bodies, abundantly clustered along the margin near the 

 ends of the intestinal diverticula, and in Bdelloura propinqua 

 extending inwards between these lobes. The seminal ducts 

 lead finally into elongated seminal vesicles, which extend 

 posteriorly parallel to the sides of the pharynx, and finally 

 curve towards the median line. They are quite easily 

 found, being of an opaque gray color. The seminal vesicles, 

 often filled with spermatozoa, open into a median pocket, 

 the atrium, which in turn opens to the exterior from the 

 oral or ventral side of the animal through a single pore. 

 The ova are conveyed to this atrium through the oviducts, 

 which are often difficult to follow. Lying lateral to the 

 seminal vesicles, one on either side, are certain disc-shaped 

 organs, somewhat larger than the ovaries, though often 

 less distinct. The function of these organs is at present 

 unknown. 



The Muscular System. Both species of Bdelloura are 

 active swimmers, and the muscular system is especially de- 

 veloped, though too difficult of demonstration to be now 

 considered. 



Drawings should be made of the several systems. 



