202 
New Trematodes 
and a completely formed and actively motile larva is present long 
before the eggs are laid. The egg-capsules vary greatly in size, those 
in the initial part of the uterus measuring about O'OIG x 0‘012 mm., 
while in the terminal part they measure 0'036 x O'OIS mm. The 
egg-capsules are, thus, less than half the size of those in Zoogonoides 
vivipay'us. 
Of the systematic position of this form there can be little doubt. It 
is without question a member of the family Zoogonidae, and of the 
subfamily Zoogoninae, bearing a close resemblance to the genera 
Zoogonus and Zoogonoides. So closely, indeed, does it resemble the 
latter, that I was at first inclined to include it in this genus. Odhner’s 
(1911) revision of the family, however, distinctly indicates that it is 
an intermediate form between Zoogonus and Zoogonoides. I have on 
that account made it the type of a new genus. Its generic characters 
may be summed up as follows: resembling Zoogonoides but differing 
in having the cirrus unarmed, in having a very highly developed 
vagina, and in possessing much smaller egg-capsules. 
REFERENCES. 
Odhner, T. (1911 a). Ziim natiirlichen System der digenen Trematoden ii. Zool. 
Anz. XXXVII, 237-253. 
- (1911 h). Zum natiirlichen System der digenen Trematoden in. Zool. Anz. 
xxxviii, 97-117. 
