60 
versely as far as the right limb of the intestine, then curves back 
and forms a central receptaculum seminis, then receives the 
vitellarian duct, and runs forward as a thick short uterus to the 
birth pore. From the distal end of the receptaculum seminis 
the paired vagina is given off ventrally. The latter consists of 
two lateral canals with glandular ends, each opening ventrally 
at the sides of the body. No eggs were seen. The vitellaria are 
much developed, occupying the sides of the body between the 
intestine and the outer wall, then unite in two main transverse 
ducts which run across the body just below the uterus to open 
into the. oviduct. Strong muscles are present, especially by the 
oral sucker and posterior disc. The disc in my specimens measures 
nearly one-third of the body, which is larger than Wierzej ski's 
figure of it. 
Family — Polystomidce, Tschbg. 
GEKVS—Octobothrium., F. S. Leuckart. 
Octobothrium merlangi (Kuhn). (Plate V., fig. 2.) Van Beneden, 
P. J., " Note sur l'Octobothrium merlangi, etc." Bull, de l'Accad. 
Koy. de Belg., torn. XXIII., 2, 1856 pages 502—8. 
This Trematode occurs very commonly on the gills of the 
Whiting on this coast ; it occurs on fully 75 per cent,, and some- 
times as many as six on one individual, usually, however, not more 
than two or three. They are to be found all the year round. 
T. Scott* records it from the Whitings of the Firth of Forth, 
and A. Scott f records it from the Irish Sea. 
The worm is pear-shaped, very much flattened dorso-ventrally, 
with the posterior broad and curled up and divided into eight 
short finger-like processes, each of which bears a chitinous sucker ; 
with these it clings to the gills of its host. The head end is very 
narrow, and bears a circular oral sucker anteriorly with two very 
small additional suckers below, one on each side. The length is 
about 11 mm., and the greatest breadth (exclusive of posterior 
processes) about 4 mm. The body is very opaque and is a greyish 
colour, with brownish vitellaria obscuring all the organs. The 
mouth leads to a very short prepharynx, and there is a large 
muscular circular pharynx leading to a narrow oesophagus which 
branches into two sinuous intestinal lobes, very much obscured by 
the vitellaria. The genital pore lies just below the intestinal fork ; 
page flo"(l!)(Tl) " Nineteenth Anm,al Report of the Fishery Board for Scotland." Pari III., 
| Scott, A., op. cit., page 36. 
