1908.] NATURAL SCIENCES OF PHILADELPHIA. 577 



d. — Shell smoothish, last whorl more or less striate. Ryu- 

 kyii, Yoronjima, C. hyperoptyx. 



d}. — Last 3 or 4 whorls sharply striate. Sezokojima, 

 Ryukyu C. h. sezokoensis. 



Clausilia nakanoshimana n. sp. PI. XXX, fig. 2. 



The shell is small and slender, the lower half cylindric, upper half 

 tapering slowly to the rather large and obtuse apex; pale brown, 

 somewhat transparent, thin, glossy, faintly striat- 

 ulate, becoming distinctly striate behind the 

 outer lip. Whorls 7^ to 7|, the earlier ones quite 

 convex, the last two much less so; last whorl 

 convex below but not saccate. The aperture is 

 broadly oval ; peristome white, reflexed and rather 

 thick, continuous. The superior lamella is mar- 

 ginal, subvertical, not continuous with the spiral 

 lamella. Spiral lamella is very low and thread- 

 like, and extends inward only slightly beyond the j jg §_ 

 lateral line. The inferior lamella recedes deeply, 

 being visible as a prominent fold in an oblique view in the aperture; 

 inside it ascends nearly vertically, is very broad and a little curved, 

 rather abruptly terminating above, not continued on the parietal wall, 

 but reappearing as a minute lamella near the inner end of the spiral 

 lamella. The subcolumellar lamella is rather deeply immersed. The 

 principal plica is dorsal and lateral. Upper palatal plica short, 

 connected to the oblique, nearly straight lunella. There are two 

 delicate sutural plicae, and a minute parallel lamella (fig. 8). 



Length 9, diam. 2.1 mm.; whorls 7f. 

 " 8, " 2.0 " " 7|. 



" 8, " 2.0 " " 7i 



The clausihum is narrow, rather long, rounded at the apex, rather 

 straight except near the filament where it bends abruptly. It is deeply 

 excised at the columellar side of the filament, and broadly dilated 

 at the palatal side. 



Nakanoshima, Osumi. Types No. 95687 A. N. S. P., from No. 1517 

 of Mr. Hirase's collection. 



This species is closely related to C. sarissa Pils. of Okinoerabu- 

 shima. It differs by the more slender shell with the last two whorls 

 less convex, and the clausilium a httle more slender and slightly twisted 

 near the apex. 

 Clausilia yaeyamensis Pils. 



Pilsbry, Proc. A. N. S. Phila., 19G4, p. 831. 



Previously reported from Yaeyama, now sent from Yonakuni-jima 



