284 s. GOTO. 



In the new species the body is of ahnost uniform breadth, 

 and presents a slightly concave border anteriorly. There is 

 also a distinct constriction at the level of the pharynx. The 

 posterior sucker is large and circular, and has 34 radii con- 

 sisting of numerous hollow chitinous hooks. These radii 

 leave the central area of the sucker free, and the most posterior 

 four or five pairs gradually decease in length backwards, so 

 that there is a backward extension of the central area. The 

 longest radii consist of about eleven hooks and the shortest 

 of only four. Each hook is hollow and strongly curved 

 at the middle, and consists of a thickened basal portion and 

 a slightly slenderer distal portion terminating in a solid claw 

 (fig. 26). The internal cavity of the hook is filled with a 

 finely granular substance, and a single oval nucleus containing 

 a nucleolus could always be observed near the basal end. At 

 the hind end of the posterior sucker there is, in the median line, 

 a roundish appendage {ajyp. post.) armed with filiform chiti- 

 nous hooks somewhat like the upper part of an interrogation 

 point. I can not exactly state the number of these hooks, but 

 I counted more than twenty. Monticelli speaks of two anterior 

 suckers ; but there is none in the new species, and their places 

 are occupied by two invaginations of the investing membrane of 

 the body, in which open numerous unicellular glands. The in- 

 vaginations are very narrow and deep, and appear like slits in 

 the mounted specimen. Each gland cell is goblet-shaped and has 

 a long neck which is much thickened just before opening into 

 the invagination above mentioned. There is one compact group 

 of these gland cells for each invagination, lying between the 

 pharynx and the lateral margin of the body ; their necks run in 

 a bundle, and their thickened terminal portions form a pear- 



