264 Larval Flakes f rom China 
glands have ducts opening at the sides of the stylet on the dorsal lip of the oral 
sucker. The only portion of the excretory system observed is the bladder which 
is oblong-ovate in contour and has heavily thickened walls and a distal pore. 
The genital cells are relatively well differentiated, with posterior, median and 
anterior elements. 
The redia in which the cercaria develops is a simple organism with simple 
contour and a digestive tract consisting of muscular pharynx and vestigial gut. 
The cercariae mature in large numbers in the rediae. 
A comparison of this cercaria with that which Kobayashi (1921) has de¬ 
scribed as the larva of Paragonimus westermanni, shows certain striking 
resemblances. While C. abbrevicauda is described as smaller, the relative pro¬ 
portion of suctorial organs, type of stylet, excretory bladder, types of cephalic 
glands, spinose integument, tail, and even the redia, are all evident signs of 
relationship. In both Kobayashi’s material and my own the differentiation 
of the two types of cephalic glands was readily effected although the exact 
number of each was not easily made out. It is important to note, also, that 
the larva is found in a species of the mollusc genus Melania. In view of the 
known records of paragonimiasis in the mountains of Kiangsi and Hunan 
Provinces in Central China and the similarity of my material with Kobayashi’s, 
it is not unlikely that this represents the larval stage of the fluke, described 
for the first time from China. 
Discussion. 
The species of cercariae described in this paper include the more common 
groups which one usually obtains from representative samplings in any area 
surveyed, such as trioculate monostome, oculate amphistome, echinostome 
and stylet cercariae. As the study of these larvae progresses subdivision of 
these larger groups on the basis of fundamental characters becomes more and 
more possible. Even though the echinostome group is a natural one with 
relatively clean cut characteristics, members of the group have differentiating 
features which can be determined by a careful study of the larva. The classifi¬ 
cation on the basis of flame-cell pattern clearly proves the applicability of 
such a method. On the other hand, the “ stylet cercariae " are an artificial 
group, only a few species of which have known correlations with adults. The 
simpler xiphidio-cercariae belong to at least three groups, Allocreadiidae, 
Plagiorchiidae and Brachycoeliidae, while the leptocercous and microcercous 
forms with a buccal stylet represent entirely different groups. It is thus seen 
that the stylet is an organ having a wide adaptation, an organ probably 
originally of definite use in penetrating host tissue. In some species it may still 
serve such a purpose, but in others a new T method of entry into the host has 
been effected, namely, passive admittance of the encysted agamostome with 
food. In this latter type the stylet never comes to function but is included in 
the cyst and soon degenerates. It is noteworthy that in all instances where 
stylets have been recorded for cercariae paired cephalic glands, emptying 
