49-i WILLIAM NICOLL. 



resembling the corresponding structure in R. ininimum. This is not 

 represented in van Beneden"s figure. 



The pharynx (ventral sucker) is situated -8 mm. from the anterior 

 end of the body. Its diameter is about -055 mm. The short intestinal 

 sac is obscured by the uterus. 



The genital glands he close together on the right side a short distance 

 in front of the mouth. The ovary is about -6 mm. from the anterior end 

 of the body and lies close up against the side. It is globular and has a 

 diameter of -1 mm. The testes are contiguous to it and to each other, 

 the first testis Ijring alongside and a Uttle in front of the ovary, the second 

 testis h^ing directly behind the ovary and first testis. Both testes are 

 globular and somewhat larger than the ovary, ha^dng a diameter of 

 •12 mm. In van Beneden's figure the testes are separated by the pharynx, 

 and what might be regarded as the ovary Hes in front. It is possible, 

 however, that that problematic structure really represents the intestinal 

 sac, in which case the ovary is not shown. 



The volk glands extend along the margins of the body from the level 

 of the ovary to a point about -25 mm. from the anterior end. The uterus 

 fills up the space between the yolk glands and passes backwards between 

 the testes and the pharynx. The ova measure •036--037 x •018--021 mm. 



The cirrus-pouch is a long slender structure which extends forwards 

 to a short distance in front of the mouth. There is a fairly large simple 

 vesicula seminalis, a long pars prostatica and a short ductus. 



Sub-Family Prosorhynchinae. 



Genus PROSORHYNCHUS Odhner. 



Prosorhynchus squamatus Odhner. 



Odhner, 1905, pp. 297-301 ; Lebom', 1908, pp. 21-3. 



This was found on two occasions in the duodenum of Cottus huhalis, 



the first time in large numbers, the second time as a single specimen. 



Prosorhynchus aculeatus Odhner. 

 XicolL 1910, pp. 350-2. 

 This common parasite of the conger was foimd in three out of four 

 specimens of the fish. 



Prosorhynchus crucibulum (Molin). 

 Xicoll, 1910, pp. 352-4. 

 This was found in association with P. aculeatus and quite as frequently. 



