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pable of closing the lip to a considerable extent and thus enclosing the 

 suckers. The genital opening is located in the middle line between 

 these suckers, it is thus entirely within the sheath, whence the generic 

 name assigned. The excretory pore is terminal. It is not clear that 

 Laurer's canal opens upon the surface. The body wall is supplied 

 Avith conspicuous scales. There is a pharynx; a small oesophagus, 

 distinctly marked by its musculature and cuticle from the two branches 

 of the intestine, the latter run backward to the beginning of the last 

 third of the total body length, terminating on the same level as the 

 vitellaria. Masses of pigment, symmetrically placed on each side of the 

 anterior end of the pharynx and in close relation with the transverse 

 and dorsally located nerve commissure, are present, and are doubtless 

 eyes, though in sections no lens could be found. There is a short 

 slender tube reaching the excretory pore at the surface from a large 

 and capacious bladder, its base lies at the level of the anterior end of 

 the anterior testis, there are two horns leading from the median part 

 of the bladder forward on each side, and reaching forward to a position 

 on either side of the pharynx. In life and in specimens mounted 

 whole these are very apparent as clear spaces on each side of the phar- 

 ynx. The smaller vessels of the excretory system have not been seen. 



The testes are oblique and posterior to the ovary. There is a 

 large seminal vesicle, but no distinct cirrus sack. A short ductus eja- 

 culatorius leads from the seminal vesicle around the posterior sucker 

 and between it and the anterior sucker and discharges in common 

 with the uterus to the exterior between the two suckers. There are 

 prostate cells, not marked off from the surrounding parenchyma, about 

 the ductus ejaculatorius at the point where it leaves seminal vesicle. 



The ovary lies dorsally and on the left side. A short tube from it 

 is joined by a duct from each side from the vitellaria and by a short 

 duct, which as indicated in serial sections ends blindly. This latter 

 passage I am inclined to regard as Laurer's canal. There is no semi- 

 nal receptacle. The vitellaria lie in the middle third of the body, reach- 

 ing a little forward of the ventral suckers, and posteriorly to the level 

 of the anterior testis. They are composed of a number of follicles. The 

 coils of the uterus occupy the posterior part of the body chiefly. The 

 organs runs directly to the hind end from its origin, coiling as it goes, 

 and then returns upon the left side, till it reaches the region of the 

 ootype where it crosses to the right sid next the ventral surface, as- 

 cends to the dorsal side behind the sheath meets the ductus ejacula- 

 torius and passes to the exterior as already described. In living speci- 

 mens I have repeatedly seen eggs pass from the uterus to the exterior 

 along the passage just described. 



