84 :Mr. W. Nicull on lU 



of the ])Ostcrior border of tlic ventral sucker and symmetri- 

 cally placed, one on cither side of this. In the living speci- 

 men it is (iitlieult to fix the exact position of the testes and 

 ovary, for they niove backwards and forwards with the move- 

 ments of the animal. Sometimes one testis is a little further 

 forward than the other, and sometimes the ovary is on a level 

 with one or b'.>th. In preserved specimens the position is 

 |)retty much as shown in the figure (I'l. II. fig. 8, T). 

 The ovary is to the rear of the ventral sucker, almost n)edian 

 or somewhat to the right. It is smaller and more globular 

 than the testes. I find the size of the miraeidium-eontaining 

 capsule to be •086-"09i x •Oi.'2-"04i mm., which is larger 

 than Od liner has it. 



Subfam. IIemivrinm (Looss, ex p.), Liihe. 



Looss * included in this subfamily the append iculate 

 Distomcs and their congeners. Liihe f, however, saw fit to 

 restrict the nauie to a certain group of these forms repre- 

 sented by two genera, Heminrus, Ilud. (ex p.), and Lccitho- 

 cltdium, n. g. Odhner later % removed Hemiurus crenatus, 

 Rud., from the former genus and made it the type of a 

 distinct genus, Brachy phallus. Of the members of this sub- 

 family we have here to deal Avith Hemiurus appendiculatus, 

 Rud., and Brachyphallus crenatus, Rud. 



Genus Hemiurus, Rud. (ex p.), Liihe. 



AVithin this genus Liihe includes only H. appendiculatus 

 (Rud., 1802), H. Stossichii (Montie., 1891), H. crenatus, 

 Rud., 1802 {= Distomuni ocreatum., Olsson, 1867), H. Icevis, 

 Linton, and H. grandiporus, Molin. These all agree in 

 having the yolk-glands compact, rounded or oidy slightly 

 lobed, situated close behind the ovary and almost touching 

 each other. The features in which they present ditferenees 

 are, amongst others, the relative sizes of the suckers, the pro- 

 portionate length of the appendix, the position of the genital 

 aperture, the length of the pars prostatica, and the position of 

 the vesicula seminalis. 



I have had before me during my investigation specimens 

 of appendiculate Distomcs belonging to the genus Hemiurus 

 from four different hosts : — Clupea harengus, Hippoglossus 



* Zool. .Jabrb. Svst. xii. p. 640. 



t Zool. Anzeig. xxiv. p. .'W4. 



I Fauna Arctica, iv. (2) pj). 3j2, 353. 



I 



