368 PROCEEDINGS OF THE ACADEMY OF [May, 



The diminutive stature together with the several characters itali- 

 cized above readily distinguish the species. Some specimens taper 

 more slowly and regularly than others, as the figures show. 



Group of C. aulacophora. 



This group passes into the group of C. validiuscula by such an 

 easy transition that it is rather difficult to draw a line between 

 them, although typical forms are so different. In the latter group 

 there are several palatal plicae standing between the upper and lower 

 ones, while in the former these plicae are united, and thereby trans- 

 formed into a lunella. 



Clausilia pigra n. sp. PI. XXI, figs. 73, 74. 



Shell rimate, rather slenderly fusiform, strongly attenuated above, 

 light reddish-brown, finely striate (or smooth by wearing or erosion 

 of the surface in some specimens). Spire very slender above, the 

 first whorl rather globose, several whorls following not increasing in 

 diameter (but in eroded individuals it is acute and tapering). 

 Whorls 10 to 10J-, convex, Ihe last compressed laterally, tapering; 

 becoming free for a short distance in front, and grooved above the 

 position of the superior lamella. Aperture piriform, subvertical, 

 the distinct sinulus retracted. Peristome continuous, white, 

 reflexed and thickened, sinuous above. Superior lamella marginal, 

 rather small, subvertical, continuous with the spiral lamella, which 

 penetrates past the ventral side. Inferior lamella immersed, deeply 

 receding, thick, straightened, branching and obliquely ascending 

 within, penetrating as far as or less deeply than the spiral lamella. 

 Subcolumellar lamella deeply immersed. Principal plica long, 

 extending from the ventral side nearly to the aperture. Upper and 

 lower palatal plicae are connected by a straight lunella, forming a 

 barrier shaped like the letter I, and exactly lateral in position. 



Length 15.5, diam. 3.3, length of aperture 3.4 mm. 



Length 14, diam. 3.3, length of aperture 3 mm. 



Length 15, diam. 3, length of aperture 3 mm. 



Clausilium narrow and parallel -sided, abruptly and deeply excised 

 on the columellar side of the filament. 



Kashima, Harima. Types No. 82,455, A. N. S. P., from No. 

 306c of Mr. Hirase's collection. 



By the shape of the aperture and the forwardly built, shortly 



