260 
Larval Flakes front China • 
There are three pairs of cephalic glands, lying on each side of the ventral 
sucker. A single, finely granular, basophilic pair lie in the plane of the sucker, 
while the two coarsely granular acidophilic pairs lie slightly anterior. They 
discharge their products through long ducts emptying at the sides of the oral 
opening. 
The excretory system consists of a compressed bladder with median dorsal 
opening, conspicuous lateral collecting tubes which divide in the plane of the 
ventral sucker to form anterior and posterior branches, and a median caudal 
collecting tube. Each of these two elements is traceable to two pairs of flame- 
cells. There are, then, eight flame-cells for each side of the body, arranged as 
(2 + 2) -f (2 + 2), represented by the formula + a li + /3 1 + ft li , with the 
basic formula a + f It happens that this expanded formula (2 + 2) + (2 + 2) 
is the one originally found to obtain for Microphallus opacus (Wright, 1912), 
and while it cannot be said with certainty that C. diophihalmica is the larva 
of* the genus Microphallus, it belongs, without doubt, to the same sub¬ 
family. 
C. diophihalmica is characterised further by the presence of a pair of 
pigmentless eye-spots (le), located on the dorsal side in the prepharyngeal 
• plane. There are also pocket spines on the inner face of the caudal pocket 
(M- 
The cercaria develops in an elongate sporocyst which is without con¬ 
spicuous marks of identification. 
Cercaria acrodonta nov. spec. 
(Plate XXII, Fig. 15.) 
This larva, for which the name Cercaria acrodonta is proposed, was secured 
from Viviparus polyzonatus Frfld. and V. quadratus (Bens.) at Wuchang during 
June, 1921. It is a minute fluke entirely covered with delicate spines. It has a 
sluggish movement, with a lash-like motion to the long heavy tail. The body 
measures 0-11 mm. in length by 0-07 mm. in width. 
At the anterior end of the body is a large oral sucker 11 /x in transection. 
The anterior (dorsal) portion of this organ appears to have a muscular adjust¬ 
ment separate from the larger posterior element, and includes the stylet 12 /x 
long, which is divided into a single median element and paired elytra. The 
ventral sucker lies in the posterior third of the larva. It has a diameter about 
one-third that of the oral sucker. 
The buccal cavity leads directly into the pharynx, which surrounds the 
anterior part of an extremely short oesophagus. The caeca are puffy pouches 
lying in the middle third of the body. The cephalic glands are unique in number 
and arrangement. They consist of seven pairs in tandem, with a middle baso¬ 
philic gland, anterior and posterior to which are a pair of acidophilic glands. 
The anterior two pairs and the posterior two pairs are basophilic. Thus the 
complete series consists of five pairs of basophilic glands and two pairs of 
