278 H. N. MOSELEY. 



but does not there give evidence of any more elaborate structure. 

 I am uncertain as to the exact nature of this structure in the 

 Land Planarians, and at a loss to explain how it is that these 

 forms should not possess a nervous system at least as highly 

 differentiated as that of Eurylepta. 



The digestive system is essentially similar in structure to that 

 in other Land Planarians. There is a single mesially placed 

 main digestive tube in the front of the body which divides into 

 two at the point of entrance into it of the pharynx and remains 

 double to the hinder extremity of the body, the two tubes em- 

 bracing between them the cavity of the pharynx and the sheath 

 containing the mass of the generative organs (PI. XX, fig. 3) . The 

 two tubes remain without communication with each other to the 

 extremity of the body. The lateral diverticula are given off as 

 in Rhpichodemus, Very short rudiments of diverticula are, 

 however, present on the inner sides of the two posterior main 

 digestive tubes which are not present in Bipalium or R/ti/n- 

 cliodemns. 



The arrangement of the openings of the diverticula into tiie main 

 canals is shown in PI. XX, fig. 6. The mouths of the diverticula 

 appear as vertically directed, irregularly oval slits which are 

 arranged in a line on the outer walls of the main canals and are of 

 two sizes, smaller ones alternating with larger. A narrow longi- 

 tudinally directed groove or depression connects the middle of 

 the mouths of the diverticula with one another. 



The pharynx is of the same simple cylindrical form as in 

 Rhynchodemus, and is contained in a sheath or cavity just as in 

 other land planarians. 



The main mass of the generative organs is packed in an elon- 

 gate cavity, with well- developed special walls situate just behind 

 that containing the pharynx. Within this cavity the organs are 

 further protected by a second investment of tough membrane 

 which divides them up into four rounded masses disposed in a 

 series or chain (PI. XX, fig. 4, a, h, c, d.) 



The organs consist of a bulbous vesicula seminalis situate most 

 anteriorly in the elongate cavity, from which vesicula a tortuous 

 and capacious ejaculatory duct leads to the large bulb of the 

 penis. An accessory bulb or sac is present in connection with 

 the penis and lower part of the male duct (PI. XX, fig. 5, x), the 

 exact relations of which to the penis were not determined. 



The penis is protruded from the single generative aperture, 

 and from this the vagina also opens, leading to the simple ovoid 

 uterus which is situate most posteriorly in the cavity containing 

 the generative organs, 



\\\ the four masses into which the generative organs are bound 

 up by their immediately investing sheath the most posterior 



