W. Nicoll 
117 
appears to be exclusively an inhabitant of the Bursa Fabricii while 
E. prosthovitellatus lives in the terminal part of the intestine. The 
latter, again, is a somewhat large species, for in E. bursicola, egg pro¬ 
duction begins when the parasite is only 1 mm. long, while in E. pros- 
thovitellatus many specimens over 2 mm. long were without ova. The 
latter species is also comparatively broader, the maximum breadth 
being always more than one-third of the length. On the other hand 
the head is distinctly narrower. The cephalic spines are a trifle larger. 
The suckers are larger and more unequal and the pharynx also is larger. 
The ventral sucker is, in addition, much nearer the centre of the body. 
Perhaps the most striking difference and that most easy of apprehension 
is the fact that the cirrus-pouch extends well past the centre of the 
ventral sucker and is not displaced to one side. In the yolk glands 
there are two noticeable features of difference. In E. bursicola the 
anterior dorsal layer does not extend so far back and the glands are 
fused in the post-testicular space. The latter condition, however, 
is sometimes met with in E. 'prosthovitellatus. Finally the eggs in 
E. bursicola are decidedly smaller. It is thus evident that in spite of 
the extremely close superficial resemblance there are several points of 
difference, the most outstanding of which, perhaps, are the position 
of the ventral sucker, the length of the cirrus-pouch and the disposition 
of the yolk glands. 
Chaunocephalus ferox (Rud.). 
A single specimen of this parasite was found in the intestine of a 
jabiru ( Xenorhynchus asiaticus ). It does not entirely agree with Dietz’s 
description (1910, p. 475) of the species. The oral sucker is decidedly 
larger, having a diameter of 0'2 mm.; the ventral sucker is also somewhat 
larger. The terminal cephalic spines are much longer and more pro¬ 
minent than shown in Dietz’s figures. They reach a length of at least 
0’21 mm. and are nearly twice as long as the other cephalic spines. 
The specimen measured 4 - 9 mm. in length and was just beginning to 
produce ova. 
