132 KANSAS UNIVERSITY SCIENCE BULLETIN. 



is nearly elliptical in outline; the dorsal body is oval, the 

 ventral flat. The body is covered with short, stiff spines, ar- 

 ranged somewhat regularly. The worm is 4.56 millimeters 

 long, 1.18 millimeters wide, and .387 millimeter thick. The 

 suckers are nearly the same size and sessile. The oral sucker 

 is subterminal and measures .392 millimeter in length and .356 

 in width; the opening has a diameter of .127 millimeter. The 

 round acetabulum is situated in the second fourth of the body. 

 It measures .453 millimeter in diameter. The genital pore is 

 on the ventral surface, very close to the left edge of the body, 

 in same transverse plane as the posterior end of the pharynx. 

 The excretory pore is at the posterior end of the body. 



The digestive system is made up of the pharynx, oesophagus 

 and intestinal caeca. The pharynx is spherical, .21 millimeter 

 in diameter. An oesophagus .36 millimeter in length follows. 

 It increases slightly in diameter as it passes posteriorly, and 

 divides into the two intestinal cseca. These are simple tubes, 

 which reach to the middle of the body. They have a diameter 

 of .07 millimeter at the widest point. The left one is slightly 

 longer than the right. 



The excretory vesicle is long and voluminous. It has the 

 shape of the letter Y. The median portion extends forward to 

 the anterior end of the testes, and the crura almost reach the 

 branching of the digestive tract. The median portion has a 

 great number of lateral, irregular outpouchings, which poste- 

 rior to the uterus nearly fill the body cavity. The walls are very 

 thin and, even in sections, are difficult to trace. The crura, 

 however, are more definite tubes, which are more regular in 

 their course. They lie mainly dorsal to the intestinal caeca, 

 and for the most part parallel. They are generally round and 

 about half the diameter of the intestinal cseca. The position 

 of the excretory vesicle is dorsal to the other organs. 



The testes are two small lobate bodies, situated slightly pos- 

 terior to the middle of the body. They are generally round, 

 though very irregular in shape, averaging .275 millimeter in 

 diameter. The very small vasa efferentia pass from the ante- 

 rior ends of the testes forward to a point a short distance an- 

 terior to the acetabulum, where they enter the vesieula semi- 

 nalis. This organ, the pars prostatica and cirrus are enclosed 

 in the cirrus-sac. The cirrus-sac is very long, measuring about 

 .50 millimeter in length. It lies ventral to the left intestinal 



