236 Gr. A. and W. G. MacCallum, 



The Oesophagus, which is wide and provided with an extremely 

 delicate wall, divides a short way behind the pharynx iuto two 

 lateral intestinal coeca which are theniselves extremely indistinct 

 in outline and so thin walled and easily torn in section that it is 

 very difficult to follow them back. They seem to have no muscu- 

 lature in their walls and quickly come to look like irregulär Spaces 

 among- the lobules of the vitellarium, never assuming- the clear cut 

 character seen in some other trematodes. Posteriorly they appear 

 to become more definitely tubulär and are elongated into the foot 

 where they give oflf long saccular branches which extend laterally 

 between the suckers. These branches are often filled with a black 

 granulär material, which marks them out very clearly. One of them 

 runs to the neighborhood of each sucker but at times they are so 

 distended that this relation is disturbed. Apparently such branches 

 run between the lobules of the vitellarium and the festes through- 

 out the body, and the same granulös, sometimes deeply colored and 

 contained in cells, can be seen in them; but one can make out no 

 musculature nor any definite epithelium in the wall. 



The nervous System seems to be very well developed, consisting, 

 as usual, of two large ganglia, one on each side of the Oesophagus 

 behind the pharynx and connected over it by a wide commissure. 

 It sends oif two broad trunks to the posterior part of the body and 

 others anteriorlj^ but one cannot trace them in the sections at our 

 disposal. 



The genital pore or cloaca lies in the median line ventrally 

 near the anterior end of the body and just at the level of the bi- 

 furcation of the intestine. It receives the outlet of the uterus and 

 the penis, the latter lying dorsal and anterior to the former. 



The penis or ejaculatory apparatus is composed of a club 

 shaped or pear shaped muscular sac made up chiefly of longitudinal 

 and oblique muscle fibre and lined with a cuticular Prolongation. 

 Within it there arises from about the middle a free narrow pro- 

 trusible tube the lumen of which is continuous backward through 

 the solid muscular fundus of the sac into a tube of similar calibre 

 surrounded by a layer of circular muscle fibres which runs backward 

 through the body. There is no definite collection of prostatic cells 

 about it. 



The coiled tube which forms a sort of vas deferens runs with 

 the most tortuous course but maintaining well the midline of the 

 body ventral to the ovary to a point at about the level of the 



