STUDIES ON THE DIGENETIC TREMATODES. 431 
diverticula separate from each other at a somewhat wide 
angle ; it is rather a division of the cesophagus into two by a 
thin septum. The two parts run side by side and their 
lumen is still lined with “cuticle.” Intestinal epithehum 
does not appear till a further distance of (05 mm., and imme- 
diately thereafter the diverticula proper arise. ‘This struc- 
tural peculiarity of the cesophagus has not been noted by 
any previous author and is not indicated in Braun’s figures. 
It is probable, however, that the small transverse parts in 
Br. palliatum and the other two species, joming the 
undivided cesophagus to the main diverticula correspond 
with the parts which I have described above, and that they 
are lined by cuticle and therefore functionally part of the 
cesophagus. Around the anterior end of the cesophagus are 
several groups of rather large cells, which probably corre- 
spond to the salivary glands of Br. palliatum as described 
by Looss. 
The diverticula occupy the lateral fields midway between 
dorsal and ventral surfaces and extend to within a short 
distance of the posterior end of the body, turning in towards 
the middle line at their termination. In addition to the main. 
diverticula a pair of smaller diverticula, one on each side, pass 
forwards and reach almost the level of the middle of the oral 
sucker. These secondary diverticula are distinctive of the 
genus. The condition of the diverticula does not differ from 
that in the other species. ‘They pursue a very erratic course, 
and numerous dilatations of various sizes, never attaining the 
size of twigs, are found both on their outer and inner sides. 
The sinuosities are so numerous and irregular that on section 
the diverticula present the appearance of being traversed by 
trabecule. The condition suggests that the diverticula, 
originally simple, had grown too long for the body and had 
become at first regularly sinuate and then crushed up to be 
accommodated in the lmited space. 
The structure of the intestinal wall is identical with that 
described by Looss. The epithelium is well developed and 
presents numerous villus-lke projections. The muscular 
