56 
A vas deferens runs from each to the oval vesicula seminalis, from 
which comes a long straight pars prostatica with a mass of large 
gland cells, after which is a small globular cirrus sac in which are 
the male and female ducts, these opening into the small genital 
sinus at the apex of a " papilla " which serves as a copulatory 
organ. The genital pore is just behind the fork of the intestine. 
The ovary is globular, behind and between the testes ; the oviduct 
runs backwards, then turns and gives off a small oval receptaculum 
seminis with a short Laurer's canal, losing itself before reaching 
the outer wall. The oviduct then receives the vitellarian duct and 
shell gland, and running forwards forms the much winding uterus, 
filling the spaces between and behind the vitellaria, testes and 
ovary, and in front of the ventral sucker, and then runs forward 
as the vagina. The eggs are golden yellow, measuring 0-059 mm. 
by 0-033 mm., and are very numerous. The vitellaria are two 
oval masses, 0-i mm. across, placed at a short distance in front 
of the posterior end of the body. A duct from each joins in a 
single one to the oviduct. 
Levinsen has found what he believes to be the young of D. 
various in the Polychffit Harmothoc imbricala. I have not succeeded 
in finding any of the larval stages. 
Genu s — He m inrus. 
Hemiarus communis (Odhner). (Plate IV., figs. 5—7.) Odhner, 
" Fauna Arctica," page 351. 
This is the only true Hemiurus that I have yet come across in 
the fishes of this coast. It occurred in four Whitings (December) 
in the stomach, in the intestine of one Bull-Head (February), and 
one Sand Eel (June). Not more than two or three examples were 
found together in the Whitings, and only single specimens were 
found in the Bull-Head and Sand Eel. According to Odbner, it is 
common in many different Scandinavian fish. Nicoll has recorded 
it from St. Andrews in the Haddock and Sand Eel. 
The worm is long and narrow, length of soma- about 2-8 mm. 
Abdomen when stretched out about two-thirds of the length of 
soma. Breadth of soma 0-5 mm., narrowing slightly anteriorly. 
The body is conspicuously striated. The oral sucker measures 
0-14 mm. across, ventral sucker 0-28 mm. across, both circular, 
the ventral sucker being placed at about the first third of the soma. 
There is no prepharynx ; the pharynx measures 0-08 mm. in 
* [ have adopted I.ooss's suggested names "soma" and "abdomen" for the body and 
^respectively. (Lcoss, " Zur Kenntnis der Distomenfamilie Hcmiuridie." Zool. Am., bd 
aaaj. (luoo, rage .j8o.) 
