258 
Larval Flukes front China 
suctorial pockets (lsp). In these pockets there are sharp spinose processes, 
which assist in locomotion of the body after decaudation. 
The oral sucker lies ventrad and measures 64/x in transverse diameter. 
The ventral sucker is situated slightly behind the middle of the body and has 
a transverse measurement of about 72 /x. Placed in the dorsal wall of the oral 
sucker is a characteristic stylet. The oral sucker leads directly into the spherical 
pharynx, while the short oesophagus is also reinforced with a muscular sphincter 
(see Fig.)- The caeca are simple pockets which extend to the region of the 
bladder. Lateral to the pharynx are paired groups of cephalic glands (acg), 
four in number, with a granular cytoplasm and acidophilic reaction. They empty 
through small ducts (cgd) at the sides of the stylet. 
The genital anlagen have not been observed. 
The excretory system consists of a vesicular bladder with enlarged anterior 
cornua, from which the collecting tubules arise, and a long channel through the 
middle of the tail, which connects proximally with the bladder. The excretory 
pore (ep) is the only opening observed for the system. After emerging from 
the lateral cornu each primary collecting tubule soon divides into five secondary 
tubules, each of which ends in three capillaries with their respective flame-cells. 
There are, therefore, 15 flame-cells on each side of the body, arising from five 
tubules of equal rank. This may be expressed as 3 + 3-f3 + 3 + 3, and 
requires a formula ofa + /3 + y + S + e, indicating that the larva belongs to 
a different group of stylet larvae than any previously reported where the ex¬ 
cretory system has been thoroughly analysed (Faust, 1919: 334). 
No cystogenous glands have been observed, but the caudal pocket setae 
{lsp) indicate that decaudation takes place. With it there is probably formed 
a thin cyst-wall around the larva. 
The sporocyst in which C. stylobuccalis develops, is a simple sacculate 
structure completely lacking differentiation. 
Gercaria styloidea nov. spec. 
(Plate XXII, Fig. 13.) 
The larva for which the name Gercaria styloidea is proposed, was secured 
from one specimen of Viviparus lecytJioides (Bens.), taken from a lily pond at 
Changsha during June, 1921, and from 0-4 per cent, of V. quadratus (Bens.) from 
Changsha during the same period. 
The body of this cercaria is oval and measures about 0-15 mm. in length 
by 0*1 mm. in width, while the tail is somewhat longer. Both body and tail 
are aspinose. 
The oral sucker is a large spherical mass directed ventrad and has a trans¬ 
verse diameter of 45 p. The ventral sucker is located far posteriad, and has 
only one-lialf the diameter of the oral sucker. The stylet is set in the anterior 
roof of the oral sucker. It has the characteristic shaj)e but has distinctive 
reinforcements in the middle of the anterior portion and sides of the posterior 
