30 
ON A NEW SPECIES OF ENTEROPNEUSTA, 
rounded cells lying irregularly internal to the limiting membrane 
in young gonads doubtless belong to it. In the young gonads 
there is present a distinct central cavity filled up in some cases by 
a deeply staining homogeneous substance. As in the other species 
of Ptychoc/era, the gonads contain large numbers of rounded or 
cubical masses of a peculiar substance which in the sexually 
immature animals fills up the gonads almost completely. It is 
found in the young gonads, both male and female, but it persists 
for a much longer time in the case of the ovaries than in the 
testes. Even in the mature ovaries traces of it remain, while in 
the mature testes no trace of it is left. Spengel regards this 
substance as nutritive in function, and the presence of the 
abundant deutoplasm in the ova readily accounts for its greater 
persistence in the ovaries. 
The ova of this species are essentially similar to those of Pt. 
minuta. They average about mm. in diameter, and 
possess very abundant granular deutoplasm. The germinal 
vesicle is very large, and contains a spongy nucleoplasm in which 
there is situated one large nucleolus and several smaller masses. 
The ripe ovum is invested in a thick egg membrane attached to 
which there may be a few very small flattened nuclei apparently 
representing the follicular layer. The heads of the ripe sperma- 
tozoa are somewhat ovoid or rounded in form, and the flagellum 
is very long and slender (fig. 26). 
Hepatic region : With the exception of the presence of two 
ciliated bands in the gut, Spengel's description of this region in 
Ft. minuta applies generally to that of this species. The liver 
sacs (fig. 24, hep.) communicate with the gut by narrow transverse 
clefts bounded by anterior and posterior lips. The wall of the 
gut is thrown into obliquely transverse folds which are interrupted 
on the dorsal side by the two longitudinal grooves, while a well 
marked furrow occupies the median dorsal region of the gut. 
The liver sacs are lined by a layer of close-set long narrow cells 
with long nuclei in a row near their base (fig. 24, ehep.). The 
cells contain numerous yellowish-brown granules, which also occur 
less abundantly in the somewhat shorter but otherwise similar 
