Terrestrial Plauarians from Jajjanese Territories. 



21 



which open in scattered distribution over the surface of the body. 



The superficial muscular system consists of the outer circular 

 and the inner longitudinal layer. The deep muscular system, 

 which is composed of longitudinal and circular fibres, is well 

 developed all round in the j^arenchyme as a thick and continuous 

 slieet. 



The mouth-opening lies near the centre of the peripharyngeal 

 ■chamber, in which is laid the pharynx plicated. The gut trunks 

 give off a large number of lateral branches, the walls of which are 

 composed of single epitlielium of high cylindrical cells. 



The cerebral-nervous system exhibits an appearance of mesh- 

 work which gives rise behind to two longitudinal nerve cords, con- 

 nected throughout by very numerous transverse commissures and 

 laterally giving off numerous nerves towards the nerve plexus. 



The common genital 

 opening leads into the vesti- 

 bulum which makes an ob- 

 lique, upwardly directed, 

 annular outbulging; conse- 

 quently there is formed in the 

 cavity a small conical and 

 downwardly directed process 

 surrounded by the said out- 

 bulging. 



Numerous testes are ar- 

 ranged in a single row just 

 along the lateral side of the 

 longitudinal nerve cords, ex- 

 tending from behind the ovary 

 to about the level of the 

 mouth. The vasa deferentia, 

 proceeding straight backwards, 

 turn abruptly upwards and forwards to enter the bulbous part of 

 the penis, and unite into a short common duct, which soon opens 

 into the seminal vesicle. 



The penis consists of the small semi-spherical bulbous part of 



a-o 



Text fig. 9. Diagrammatic representation 

 of the genital organs of Bijnilitim fitscoHneattim, 

 n, sp., as seen from the dorsal side. 



Index letters as in text figs. 1 and 3. 



