E. C. Faust 
207 
the described species of this group. The oral sucker measures ()• 148 by 0-165 mm., 
while the acetabulum which is situated slightly anterior to the middle of the 
body measures 0-115 by 0-113 mm. The pharynx has a transverse diameter 
of 43 fjb. Anterior to the acetabulum is the conspicuous genital pore. From 
the pharynx the coeca first extend laterad and then posteriad, ending just 
anterior to the excretory bladder. These coeca are long narrow pouches as 
distinguished from the large thick-walled ones of the closely related species, 
C. brookoveri. 
The genital organs are but poorly developed in C. pekinensis , even in the 
most mature individuals. However, the two testes have become differentiated 
and a lobate body anterior to them is connected by a heavy cord of genital- 
gland tissue to the genital pore anteriad. In this respect C. pekinensis repre¬ 
sents a type somewhat more mature than C. brookoveri, although it does not 
approach the degree of maturity of C. macrostoma. 
Neither cephalic nor cystogenous glands have been seen in the larva. The 
body parenchyma consists of a close network of tissue. In the tail trunk, 
however, the parenchyma is extremely loose and vacuolated, with small con¬ 
densation nuclei only at the interstices. On the other hand the furci have a 
close network of tissue like the body. 
C. pekinensis develops in a sporocyst characterised by an anterior end 
with pharyngeal sphincter but without a gut. At regular intervals along the 
body the contracted sporocyst (Fig. 5) has annuli of integument and muscular 
tissue, which disappear, however, when the animal elongates. In this respect 
it is strikingly similar to the sporocyst of C. brookoveri. The sporocyst with its 
enclosed larvae has a rapid shuttle-cock movement. 
There are two or more generations of sporocysts. Some sporosacs are found 
to contain nothing but developing sporocysts. Others contain both sporo¬ 
cysts and cercariae. Still others contain cercariae alone. Only a few flukes 
develop within the parthenita at one time. The tail becomes differentiated 
from the body soon after the germ-ball stage is passed; but the furci appear 
late. At the time when the furci first become distinguishable from the tail 
trunk the oral and ventral suckers are well developed. The pharynx is clearly 
marked off, but the digestive coeca, while readily observed, only extend a short 
distance posteriad. At this same stage there is a distinct genital cord extending 
longitudinally across the face of the acetabulum, suggesting an early sexual 
maturity in the worm which is not carried out in subsequent development. 
No encystment of C. pekinensis has been observed nor does the worm readily 
part with its tail. It seems probable that the fluke passes directly into the 
subsequent host without a latent period. 
