1 24 Quarterly Journal of Conchology. 



Shell subulately conical, decollated, brown ; the 3 remaining 

 whorls almost fiat, separated by a simple and somewhat oblique 

 suture, furnished with about 15 longitudinal slightly slanting ribs 

 and 3 spiral lirations which are nodulous at the points of intersec- 

 tion with the ribs, and also striated by the fine lines of growth ; 

 the last whorl girded below the middle by 2 — 3 less or scarcely 

 nodulous spiral lirations ; the aperture moderate, obliquely pear- 

 shaped, at the base a very little pointed, 'of a bluish-white colour 

 within ; the columella scarcely arched above, moderately curved 

 below, joined to the outer lip above by a thin callous enamel. 



Var. 



Shell smaller, either olive or olive-brown ; the whorls rather 

 more convex, with the longitudinal ribs closer together and slightly 

 arcuate, and 5 — 7 spiral lirations more slender and less nodulous 

 at the points of contact. 



Hub. Lake Biwa, near Kiyoto. 



This is a very distinct species from all others which have 

 hitherto been recorded from Japan. The tubercles at the points 

 of conjunction of the costations and transverse lirations are very 

 conspicuous in the typical form. The costse u/e more prominent 

 than the lirje, indeed the latter are almost obsolete between the 

 longitudinal ribs ; but such however is not the case with the two 

 or three which are situated below the middle of the body whorl, 

 these are less nodose or even quite devoid of tubercles and are 

 well developed. 



The smaller variety is mainly distinguished by its slightly more 

 convex whorls, and the closer arrangement of the ribs which are 

 obliquely arcuate. I know of no species with which to compare 

 the present form, perhaps M. Aimirensis of Gerstfeldt offers as 

 much similitude as any, however its much larger size, more tur- 

 reted whorls and much stronger costations are differences which 

 at once dissociate it from M. Nipo?iica. Theiigureof J/ Morc/iiim 

 Reeve's Conchol. Icon. f. 108 represents very fairly the outline of 

 the typical form of this species ; the variety is much more slender. 



16. Melania tenuisulcata Dunker. — -"Plentiful in rapid 

 streams and on moist rocks," Yokohama. Three 

 other species have been described which are most 



