28 Art. 4. — T. Kaburaki : 



The mouth-opening whicli leads into the peripliaiyngeal 

 chamber is situated near the centre of the body. 



The genital aperture is placed at the hind end of the second 

 third of the distance between the mouth-opening and the posterior 

 end of the body. 



The epidermis is composed of a layer of columnar cells, which 

 are very much higher on the dorsal than on the ventral side. The 

 cilia are confined to the surface of the sole only. Evidently situat- 

 ed between the cells are minute rhabdites which take place in the 

 subcutaneous cells. Besides the glands opening medially on the 

 surface of the sole, there are some unicellular glands which open 

 in scattered distribution all over the surface of the body. 



Directly below the basement membrane comes a muscular 

 system which consists, as usual, of the outer circular and the inner 

 longitudinal layer. Deep below^ these layers, in the parenchyme, 

 is a thick and continuous sheet composed of two distinct sets of 

 fibres, longitudinal and circular, which occur intermingled in the 

 same sheet. In addition to these are found the dorso-ventral mus- 

 cles which run between the gut diverticulae. 



The mouth-opening is situated in the middle of the peripha- 

 ryngeal pocket, from the dorsal wall of which arises the plicated 

 pharynx. The intestinal trunks are provided with numerous 

 branches which are sometimes bifurcated and sometimes trifurcated. 

 Their walls are a single epitlielium made up of high cylindrical 

 ■cells Avhich are placed very closely together and contain numerous 

 coarse, highl3^-refractive granules in the finely granular protoplasm. 



The brain has the appearance of meshwork, widely spread at 

 the anterior end of the body. Posteriorly from the meshwork 

 spring two longitudinal nerve cords which proceed backwards, 

 running nearly parallel to each other, to the hind end of the body, 

 and are connected by numerous transverse commissures. Laterally 

 they give off numerous branches. 



The eye consists simply of a pigment cup, filled with a cellular 

 substance, which is a faintly staining, very slightlj' granular body 

 and very little differentiated from the general cell-contents. 



