248 



S. GOTO. 



ing to Taschenberg, wholly continuous with each other along the 

 posterior border of the body. 



i. Tristomum foliaceiim, n. sp. 

 (PI. XXIV, figs. 10-12; PL XXV, fig. 9.) 

 BolIij elongated, slightly ovate, about 6 mm. by 3 mm. ; 

 with the anterior border brace-shaped (— ); lateral margins entire, 

 destitute of any chitinous corpuscle, and divided from the median, 

 anterior lobe of the body only by a slight constriction^ where the 

 anterior suckers are attached ; Avith a not very deep notch at the 

 posterior end. Anterior suckers circular, of moderate size in com- 

 parison to the body. Posterior sucker slightly elliptical, with the 

 major axis directed antero-posteriorly, projecting beyond the body by 

 about one-third of its length ; provided with a marginal membrane ; 

 with a diameter equal to the breadth of the body just behind the 

 anterior suckers ; its internal surface divided into areas just as in 

 T. ovale. Hooks in one pair, in position as they are in T. ovale, 

 hollow, spinous, with a deep notch at the proximal end, of the form 

 represented in fig. 11, PI. XXIV, about 0.175 mm. long on the 

 average. In the specimen examined by me the hooks were of unequal 

 lengths on the two sides, that of one side being 0.164 mm. and that 

 of the other 0.186 mm., thus giving the average above recorded. 

 3Iouth of moderate size, at the plane of the hinder end of the 

 anterior suckers. Pharynx divided by a constriction into two unequal 

 portions as in T. ovale. Oesophagus very short. Intestinal trunks 

 continuous with each other behind, a little in iront of the posterior 

 sucker, with numerous dendritic branches on the outer side, and with 

 a few shorter branches on the inner ; enclosing a not very ex- 

 tensive area in the middle portion of the body similar in form to 

 that of the latter. Common (jenital opening a little on the left side of 



