1900.] NATURAL SCIENCES OF PHILADEL1MI I A. 679 



flexed peristome, the superior lamella separated by a hiatus from the 

 spiral lamella; subcolumellar lamella emerging, running to the mar- 

 gin. Principal plica short, extending but slightly or not at all in- 

 ward beyond the upper palatal plica. Palatal plica; four, the upper 

 quite long, the lower bow-shaped or arched, the two ends bent 

 downward; the two intermediate plicrc short. Clausilium narrower 

 than in C. japonica, the palatal margin obliquely sloping toward 

 the apex, which is thickened and obtusely rounded; columellar 

 margin slightly excised or subemarginate near the filament, or 

 merely tapering there. 



Length 28, diam. 6 mm. 



Length 28, diam. 5J mm. 



Length 23, diam. 5J mm. 



Ibuki, Omi (Mr. Y~ Hirase). 



The shell does not differ strongly from C. japonica, certain 

 forms of which have the superior and spiral lamellae disconnected, 

 and sometimes there are four palatal plicae; but the shape of the 

 lower palatal plica or fold is different, it being short and oblique 

 in C. japonica, not arched as in this species. The shape of the 

 clausilium, however, is strikingly unlike in the two species, that of 

 C. japonica (+ nipponensis -f- kobensis) being constantly broader, 

 with pointed apical end, in specimens examined from some four- 

 teen localities. This will be suitably illustrated in a future com- 

 munication, as the space on my plates does not allow figuring at 

 this time. 



Section HEMIPHJSDUSA Bttg. 

 (Group of C. validiuscula. ) 

 Clausilia Nolani n. sp. PI. XXV, figs. 19, 20, 21. 



Shel) rimate, fusiform, attenuated above, solid, of a dark- 

 brown color; distinctly but finelt striate. Whorls 10, moderately 

 convex, separated by impressed sutures, the outlines of the spire 

 somewhat concave above; last whorl a little compressed. Aper- 

 ture squarish-ovate, hardly oblique; sinulus short, retracted; 

 peristonie brownish, expanded, subreflexed and thickened, contin- 

 uous and free above, and slightly or not emarginate there. Supe- 

 rior lamella somewhat oblique, very widely separated from the spiral 

 lamella, attaining the margin. Inferior lamella scarcely emerg- 

 ing, but slightly visible from in front, bifurcate and straightened 



