54 
inside the capsule (the capsule measuring 0-07 — 0-08 mm. in 
length), and many are very active and can be seen rushing about 
when pressed out. They are pointed at one end and bluntly trun- 
cate at the other, and are covered with constantly moving long 
cilia. The vitellaria are much reduced, and are in the form of a 
; compact round mass to the left of the ovary, from which a duct 
is given off to the oviduct. 
This worm occurs in 10 per cent, of the Dab and Long Eough 
Dab, and in one Plaice out of three examined. 
The life history is unknown. 
Genus — Lecithaster. 
Lecithaster gibbosus (Rud.). (Plate IV., fig. 3.) = Distomum 
malissimurn (Lev.). Odhner, " Fauna Arctica," page 356. 
This delicate species I have found twice in the intestine of the 
"Whiting (June and October), and once in the intestine of the Grey 
gurnard. The latter fish is, I believe, a new host for this worm. 
Odhner says it is present in many northern fish. Nicoll obtained 
it once at St. Andrews from the Sand Eel, and Johnstone * got it 
from Belone vulgaris on the Lancashire coast. I have always found 
it in numbers in .its hosts. It is an exceedingly fragile species, 
and very transparent. The usual length is about 1-2 mm., the 
greatest breadth being about a third of the length. It is colour- 
less, except the eggs, which are a pale greenish-brown, and the 
body is unarmed. The posterior end is slightly constricted off and 
sometimes looks like a short tail. The suckers are circular, oral 
sucker 0-10 mm. across, ventral sucker 0-20 mm. and placed in 
front of the centre of the body. There is no prepharynx, the 
pharynx measures 0-06 mm. long, and there is a very short 
oesophagus branching into two rather thin lobes, which reach 
nearly to the end of the body. The excretory system consists of 
a thin central stem branching near the middle of the body and 
uniting behind the pharynx. It is filled with a highly refractive 
contents. The testes are globular, somewhat dorsally placed a 
little way behind the ventral sucker, each giving off a short vas 
deferens, which goes to the vesicula seminalis without uniting with 
its fellow. The vesicula seminalis is large and spherical, placed 
at the left of the ventral sucker. In front of it is a long and well- 
developed pars prostatica accompanied by large gland cells, and 
this leads to a small cirrus sac, at the beginning of which the 
* Johnstone, op. cit. (1906), page 185 
