22 Br. W. NicolT on tJie 



and sprat, but I have to record its occurrence on at least one 

 occasion in the stomach of Trigla gnn\ardxis. It is rarely 

 absent from the herring, bnt is more seldom found in the sprat, 

 being present in only about 10 per cent. In the latter fish 

 it is not confined to the stomach, but may be found in the 

 oesophagus, caeca, and even the intestine. 



It is readily distinguished from Hemturus commiinis by 

 the comparatively enormous length of tiie pars prostatica, but 

 this does not serve to separate it from //. ajypendiculatus. 

 The specific features of H. liihei are: — length of soma 

 l'5-3'5 mm. ; average breadth ^ of length ; ecsoma not 

 more than ^ length of soma, frequently much less; neck not 

 more than -^ of soma. The limits ^^-^q for the neck given 

 by Odhnerare certainly much too small, although they serve 

 to emphasize the fact that the suckers are more approximated 

 in //. liihei than in U. communis and H. append iculatus. 

 The diameter of the ventral sucker is i ^- ^q of the length of 

 the soma, and it is thus relatively much smaller than in the 

 other two species. The sucker-ratio is 3 : 5 in such a large 

 number of my specimens that I am inclined to regard that as 

 fairly constant and more accurate than the ratio which Odhner 

 gives, namely 2:3. In some of my specimens it certainly 

 reaches 2 : 3, but in others it falls as low as 1 : 2. Both diver- 

 gences are probably due to contraction of one or other sucker. 

 The oesophagus is almost entirely absent. The genital sinus 

 extends back as far as the anterior border of the ventral 

 sucker; the vesicula seminalis is bipartite, the anterior part 

 being muscular, the other not, and it is situated far behind 

 the ventral sucker (about ^ of the length of the soma). The 

 testes lie immediately behind the vesicula, and as the ovary 

 lies at about the same level as in Hemiurus communis it follows 

 that the genital glands are closer together than in that 

 species. 



Distomum sp. 



From the rectum of Cyclopterus lumpus a small immature 

 Distome was obtained, the identity of which I have not been 

 able to determine. It was elongated, more pointed posteriorly 

 than in front, and measured about "5 mm. The body was 

 entirely covered with spines. The oral sucker was slightly 

 larger than the ventral sucker ; the latter situated rather 

 behind the middle of the body. Long prepharynx ; small 

 pharynx; small round sac-like excretory vesicle*. 



* A number of specimens of the same form, again immature, have 

 recently been found by my friend Mr. William Small. The species 

 apparently belongs to the genus Lepidapedon {Lepodora), but its identity 

 with either of the already known species of that genus is not evident. 



