384 
S. .r. JOHXSTOX. 
sac. Ovary spherical; Laurer’s canal and receptaculiun 
present; uterus small; yolk-g*lands very richly developed. 
Parasitic in the intestine of Tetraodon hispidus Linn. 
Type specimen in the Museum of the Australian Institute 
of Tropical Medicine^ Townsville^ No. T. 37. 
Co-type in the Australian Museum, No. AV. 367. 
The largest specimen, fixed under slight pressure, measured 
12 mm. long by 5 mm. broad; the smallest from the black 
toad-fish (Tetraodon hispidus ?) 8 mm. long by 3*75 mm. 
broad. Eight specimens were obtained from this host ; but 
a large number of specimens, which differed from these only 
in being smaller in size, 5-6 mm. long by 2 mm. broad, 
were obtained from the intestine of the spotted toad-fish 
(Tetraodon hispidus). The worms are flat and almost 
rectangular in shape in the preserved specimens, the sides 
being fairly parallel and the ends almost truncated. 'I'he 
integument is thick and shows a number of corrugations on 
the surface. There are no spines. 
The oral sucker is very large and strong, in many cases 
retaining within its grasp a piece of the mucous membrane of 
the host’s intestine. It measures P666 mm. in diameter. 
The opening is terminal and comparatively small, with a 
condensation of the tissues round its edge so that the latter 
is specially tough. The ventral sucker is much smaller and 
weaker, and measures O’ 7 14 mm. in diameter. The ratio of 
the oral to the ventral sucker is 7 : 3. The phaiynx is^a little 
smaller than the Amntral sucker, and in most cases was com- 
pressed in the longitudinal direction. There is a distinct 
prte-pharynx, and a short oesophagus 0’12 mm. long (fig. 38) 
leading into the intestinal limbs, which run at first horizon- 
tally, where they bend round to become longitudinal ; a 
ctecum is given ofi which extends forwards as far as the 
middle of the anterior sucker. The main posterior limbs, 
which are wide, extend straight back, parallel with the sides 
of the body, into the extreme posterior end. They have no 
branches, but in contracted specimens the walls are thrown 
into transverse folds. 
