2Q Art. 4. — T, Kaburaki : 



situated between the epidermic cells. Directly below the super- 

 ficial muscular system, there occur such rhabdites as are still con- 

 tained in their mother-cells. There are enormous quantities of 

 slime glands which are deeply situated in tlie parenchyme along 

 the median zone of the body and open out on the surface of the 

 sole. 



The superficial muscular system is composed of the outer 

 circular and the inner longitudinal layer. 'J'he deep muscular 

 system, which chiefly consists of longitudinal fibres, is well deve- 

 loped all round in the parenchyme as a continuous sheet. In 

 addition to these, dorso-ventral muscles are found, running be- 

 tween the branches of the intestine. 



The mouth-opening is situated near the centre of the peri- 

 pharyngeal chamber with the plicated pharynx hanging from above. 

 The three main gut trunks are provided with numerous outwardly 

 directed, lateral branches which are sometimes bifurcated and 

 sometimes multifurcated. The lining epithelium of the intestine 

 is made up of high cylindrical cells which contain a great number 

 of coarse, highly refractive granules in tJie finely granular proto- 

 plasm. In some cases the cells were seen to be vacuolated in the 

 distal portion of the cell. 



The cerebral nervous system has the appearance of meshwork 

 which is continuous with two longitudinal nerve cords, running on 

 either side of the median line. Throughout their entire course, 

 the cords are connected by very numerous transverse commissures. 

 Laterally they give otï numerous branches towards the nerve plexus, 

 lying beneath the outer longitudinal muscles of the body and ex- 

 tending completely round the body. 



The common genital aperture leads into the vestibulum 

 which forms an oblique, upwardl,y directed, annular outbulging; 

 consequently there is formed in the cavity a downwardly directed, 

 conical process surrounded by the said outbulging. The cavity is 

 lined with a single epithelium, beneath which is a muscular coat- 

 ing composed of circular and longitudinal fibres. 



Numerous small testes, each made up of sperm-mother-cells 

 and spermatozoa in several stages of development, are arranged in 



