29 
ACANTHOPSOLUS LAGENIFORMIS, N. Sp., 
A TREMATODE IN THE CATFISH. 
By MARIE V. LEBOUR, M.Sc., 
Assistant Lecturer and Demonstrator in Zoology, Leeds University. 
The following work w T as done entirely at the Dove Marine 
Laboratory, Cullercoats, from material brought in by the fishing 
boats. 
Distomuw, sp., Lebour, “ Fish Trematodes of the Northumber- 
land Coast,” Northumberland Sea Fisheries Report for 1907, p. 81, 
Plate III., figs. 6 — 8. 
A brief and incomplete description of this Trematode was given 
by myself in the above-mentioned paper. Nicoll (1) is of the 
opinion that it is closely allied to Acanthopsolus Odhner (2) and 
the differences are so slight that it seems hardly justifiable to found 
a new genus for it. 
The worm occurs frequently, and in great numbers in the upper 
part of the intestine of the Catfish Anarrhichas lupus. It is by no 
means always present, but occurs in about 40 per cent, of the local 
Catfish in Spring, Summer, and early Autumn, i.e., from April till 
October, being rarer in Spring than in Summer, and disappearing 
in the Winter altogether, repeated search for it in the Winter 
months being unsuccessful. Two Catfish from Shetland brought 
in by the North Shields boats (April, 1909) both also contained the 
worm. The usual habitat is the creamy, opaque, and very thick 
intestinal slime just beyond the stomach. The worm gets 
entangled in this, and it is very difficult to get it completely away 
from the slime which must act as an effective obstacle to its being 
swept away with the intestinal contents of its host, the suckers 
being apparently too weak to make any hold on the walls of the 
intestine. The stomach is sometimes also infected as well as the 
mouth and pharynx, but usually the younger stages occur in these 
latter regions, and the anterior portion of the intestines seems to 
be the true habitat. There may be hundreds present in one fish, 
and there is always a great number if the worm occurs at all. 
