198 
New Trematodes 
Ancylocoelium tyioicum, n.g., n.sp. (PL IX, fig. 1). 
This is a moderately small Trematode measuring 2’25 mm. in length 
and 0'48 mm. in maximum breadth. It is decidedly flattened dorso- 
ventrally and its outline is somewhat spatulate, the greatest breadth 
occurring in front of the middle of the body, whence it tapers sharply 
to the anterior end and more gradually to the posterior end. The 
average breadth in the posterior half of the body is 0'28 mm. In life 
the animal has a rich yellow colour from the enormous number of eggs 
which it contains. The cuticle is beset for the greater part of its extent 
with small scaly spines, which disappear gradually towards the posterior 
end. 
The suckers are small and inconspicuous. The subterminal oral 
sucker has a diameter of OTO mm., while the ventral sucker measures 
T3 mm. The latter is situated at a distance of 0‘92 mm. from the 
anterior end. 
The somewhat elongated pharynx follows almost immediately on 
the oral sucker and measures 0‘08 x 0'043 mm. The oesophagus is long 
and narrow. Its length is about O'o mm. and the bifurcation takes 
place a short distance in front of the ventral sucker. The intestinal 
diverticula are of unique configuration. They are considerably wider 
than the oesophagus and instead of passing round the ventral sucker 
they are bent back abruptly into the anterior part of the body. They 
diverge at a fairly wide angle, passing out towards the sides of the body, 
but when they have nearly reached the margin they are again bent 
somewhat acutely and pass back almost straight. They terminate a 
short distance behind the level of the intestinal bifurcation. 
Owing to the enormous mass of eggs, only the terminal part 
of the excretory vesicle could be observed even in the living specimen. 
The genital system presents several peculiar features. The anterior 
testis is situated somewhat to the right side, a short distance behind 
the ventral sucker, from which it is separated by the ovary. The 
posterior testis lies more median, not far behind the anterior testis 
(0*22 mm. behind the ventral sucker). Both are elongated oval and 
measure about 0'19 x O'lO mm., their long axes being slightly oblique 
the long axis of the body. The cirrus-pouch is of simple type and 
IS situated over and in front of the right anterior quadrant of the 
ventral sucker. Posteriorly it is almost contiguous with the ovary and 
the anterior testis. It shows the usual shape and contains a large oval 
vesicula seminalis. Its dimensions are 0’32 x OTl mm. There is a 
