ICntnzoii from the Mm-tiuift ('oust. r>05 



course towards the middio of tlic se;i;inent. The testos are 

 very numerous (:il)out one hundred), extending tiiroughout the 

 nieduUmy jMirfrichynie on eith(»r side of the female glands. 

 The ovary consists of two symmetrical l)niiches of lobes 

 situated in the nuil<ile of the segnnMit. The yolk-gland is 

 situated at the back of the segment. The 8hell-;'lan<l is a 

 conspicuous organ lying between the ovary and the yolk- 

 f{land. The vagina rurjs fairly straight from the genitnl 

 pore to the mi'hlle of the segment, its inner end, functioning 

 as a receptaculum seininis, persisting in the gravid segmetits 

 after most of the other organs have disappeared. Tlie oviduct 

 becomes very wide hefort; opening into the uterus, running 

 vertically for the last portion. The uterus appears at first as 

 a transverse tube, but afterwards disappears, and numerous 

 egg-capsules are formed. 



The most important character distinguishing this form 

 from the typical />. tf(ra(]ona is the much larger number of 

 testes (twenty to thirty in 1). tetragona^ about one hundred 

 in the present variety). 



Dilepinidae. 



Lateriporus teres ( Krabbe), Fuhrmann, 1907. 



Host: Somateria molUssima. Yukanski, 8. vi. 1917 ; Pet- 

 schetiga, 24. ix. 1917. 



This species seems to be fairly common in the eider-ducks 

 in this region. It was met with in two individuals obtained 

 at the first-given locality, and in another at the second. 



Choanotcenia paradoxa (Rud.), Clerc, 1903. 



A single specimen, probably referable to this species, was 

 obtained from a re(l-neckfd phalarope ( P/talaro/nis lolxitim) 

 at Yukanski, 10. viii. 1917. 



Choanotcenia sp. (?). 

 (Not Ch. borealia (v. Linst., 1905), Fuhrmann, 1908.) 



Host: Clatmula ht/etnalia [=r I/arelthi glacinlis] (long- 

 tailed duck). Vukanski, 8. vi. 1917 and 10. vi. 1917. 



There are .'several fragments of what appears to be a species 

 of Cliodiiotirnid, or possibly Anomnffenia, obtained on 

 different occasions from two long-tailed duck-». Unfortu- 

 nately, however, there is only one scolex, and this has lo'St its 

 rostellum, so that the characters of th" h>'k->, so important 



