674 PROCEEDINGS OF THE ACADEMY OF [1900. 



striation is stronger. C. tau is a widely distributed species with 

 long upper palatal plica and stronger lunella, etc. 

 Clausilia monelasmus n. sp. PI. XXIV, figs. 4, 5, 6. 



Shell rimate, slender, fusiform, strongly striate, brown. Apex 

 rather acute, but the nuclear whorl is somewhat swollen; spire 

 attenuated above. Whorls 8J to 9, quite convex, the sutures 

 well impressed, the last whorl narrower than the penultimate. 

 Aperture hardly oblique, pyriform, with rather indistinctly denned, 

 retracted sinulus. Peristome thickened, expanded, continuous, 

 white. Superior lamella wanting, represented by a slight thick- 

 ening of the peristome at its position; spiral lamella arising so far 

 within that it is not visible from the aperture, but becoming high 

 and continued to the ventral side, being longer within than the 

 other lamellse. Inferior lamella obsolete below, not emergiDg, but 

 high within, as in C. digonoptyx. Subcolumellar lamella deeply 

 immersed. Principal plica very short and small, lateral. Upper 

 palatal plica strong, its lower end bent downward; lunella want- 

 ing; lower palatal plica short, well developed. Clausilium (PI. 

 XXV, figs. 26, 27, 28, 29) short and broad, strongly curved, 

 not emarginate behind, and only slightly thickened apically. 



Alt. 10.5, diam. 2.3 mm. 



Kayabe, Ojima (Mr. Y. Hirase). 



This is the first Clausilia to be made known from Hokkaido 

 (Yesso), to my knowledge. It occurred with a small Hemi- 

 phcedusa. It is remarkable for the obsolete condition of the supe- 

 rior lamella, the deeply immersed spiral lamella and the wide 

 interruption of the lunella, the remaining ends of which appear 

 merely as upper and lower palatal folds. A white line may be 

 seen on the parietal wall, on looking into the aperture, caused by 

 the subcolumellar lamella showing through. 



( Group of C. jos. ) 

 Clausilia iotaptyx n. sp. PI. XXV, figs. 7, 8, 9. 



Shell rimate, turrited, the penultimate whorl widest, those above 

 nearly regularly tapering, then becoming almost cylindrical, the 

 apex obtuse; rather solid, finely striate, a little more coarsely so 

 on the back of the last whorl. Whorls nearly 11, but slightly 

 convex, the last compressed. Aperture hardly oblique, ovate- 

 pyriform, the peristome well expanded, slightly thickened, whitish, 



