Oll SlicLocutylc tiephrupis Cunniii;;liRrii, n pHrusito of the Ainericau lobster. 465 



fiirther back than in the case represeutetl in the drawing (PI. 31, 

 Vï'^. 23). In sections of one worm it was found to be h)cated about 

 half way between the mouth and the first sucker. I'here is, however, 

 only one place of communication between the collecting tubules of 

 each side of the body and the large lateral vesicle of the corresponding 

 siile. Between the tubules of opposite sides there is no connection 

 whatever. 



Tlu; general method of branching and the distribution of these 

 collecting tubules may be seen from the drawing (PI. 31, Fig. 23). 

 On each side of the body a single tubule opens into the vesicle near 

 its anterior end. These tubules extend backward and give off numerous 

 branches. From that of the right side the first to be given off is 

 about midway between the se.xual opening and the anterior end of 

 the body; it extends backward but a short distance before being lost 

 in capillary branches. The second branch is given off at a point 

 opposite the sexual aperture; it extends forward and is distributed to 

 the vicinity of the mouth and pharynx. The third branch arises 

 just behind the first sucker and passes backward to the vicinity of 

 the right testis. In the vicinity of the third, fourth and fifth suckers 

 several short branches are given off, which are distributed to adjacent 

 portions of the body and the oviduct. In the posterior fourth of the 

 body the main tubule divides into two branches, which become gradually 

 smaller and are finally lost near the posterior end. The branches of 

 the main tubule of the left side differ somewhat from those of the 

 riglit. There is here no branch corresponding with the first on the 

 right side. The first branch to be given off is opposite the second 

 branch of the right side and divides into several sub-branches, which 

 extend both forward and backward to the region between the anterior 

 end of the body and the second sucker. The second branch arises 

 opposite the third sucker and is distributed to the portion of the 

 body opposite the second and third suckers. Near the fourth sucker 

 a branch is given off which passes to the region of the ovary and 

 the left testis. Behind the seventh sucker the tubule divides and the 

 two portions reach backward and are lost near the posterior end of 

 the body. 



In the living animal long cilia may be seen in the lumen of the 

 tubules attached to their walls at intervals; they lie along the axis 

 of the lumen with the free ends directed cephalad and keep up a 

 constant undulating vibration which is not too rapid to be followed 

 by the eye. The length of these cilia is two or three times the 



