Two New Trematodes of the Family G\rodactylidae. ] Q 



end starts the oviduct, which proceeds straight forwards along the 

 median line of the body and is continued into the ootype a short 

 distance in front of the ovary. There is a light constriction at 

 the boundary between the oviduct and the ootype, where the 

 glands of JIehlis open ; these are aggregated into a comparatively 

 narrow space between the intestinal cœca on either side, the ovary 

 behind and the posterior prostate iu front. The gland cells stain 

 about as well as or slightly better than those of the anterior 

 prostate. The ootype is continued without any sharp demarcation 

 into the uterus, which runs forwards and opens to the exterior 

 directly behind the male pore. The uterus is provided with 

 longitudinal and circular muscle fibres. 



Immediately behind the ootype, the oviduct communicates 

 with a small chamber on its dorsal side, which bears a tongue- 

 shaped sac, the receptacuhtm seminis, lying on the dorsal and left 

 side of the oviduct and extending for a short distance forwards 

 from its connection with the latter (fig. 14). A curious fact in 

 connection with it is that a slender canal proceeds backwards from 

 its hind end and becoming gradually finer, terminates blindly near 

 the front end of the ovary — probably a homologue of the genito- 

 intestinal canal found in many other Heterocotylea. The short 

 neck of the seminal receptacle is provided with sphincter fibres 

 and the sac usually contains spermatozoa. According to Wegener 

 [p. 210] a similar receptacle is present in Ancyrocejy/tah's 

 paradoxus, but the tail-like prolongation appears to be lacking. 



The vitellarium appears to be less well developed than in 

 Dactylogyrus and surrounds the intestinal cœca on all sides except 

 the inner; behind the posterior intestinal loop it is also found 

 between the cœca of either side. The paired yolk ducts, which 

 are formed each by the union of two ducts arising from the 

 vitellarium at about the level of the anterior end of the ovary, 

 proceed inwards and uniting in the median line on the ventral 

 side of the oviduct immediately open into the latter. Into the 

 small chamber above mentioned on the dorsal side of the oviduct 

 opens the vaginal canal obliquely from the right and dorsal side, 

 whence the canal proceeds obliquely forwards and towards the 



