380 PROCEEDINGS OF THE ACADEMY OF [^^ay, 



Clausilia una Pilsbry. PI. XXI, figs. 66, 67, 68, 69. 



These Proceedings for 1901, LIII, p. 656, footnote No. 14 (March 1, 

 1902). 



Shell regularly tapering above, attenuated near the apex, very 

 solid and strong, pale yellowish, slightly glossy, regularly, closely 

 striate, the striation becoming much coarser on the back of the 

 last whorl. Whorls 11^ to 12, moderately convex, the penulti- 

 mate widest. Apical whorl globose, the next 2 or 3 whorls hardly 

 increasing in diameter, last whorl a little compressed. Aperture 

 ovate, hardly oblique. Peristome thickened and reflexed, continu- 

 ous, shortly free above, a little notched or emarginate at the position 

 of the superior lamella, the entire upper and right margins closely 

 and deeply plicate. Superior lamella slender, subvertical, mar- 

 ginal, continuous within with the spiral lamella, which is high 

 laterally, and continues inward to a point above the sinulus. In- 

 ferior lamella bifid, appearing as a double fold below, ascending in 

 a wide spiral, and continued inward as far as the spiral lamella. 

 Subcolumellar lamella emei'ging to the lip-edge. Principal plica 

 over a half -whorl long, visible deep in the throat and extending 

 inward to the ventral side. There is a small upper palatal plica, 

 lateral in position and converging inward toward the principal 

 plica, and a much longer, arcuate, lower palatal plica, from the 

 middle of which a very short, rudimentary lunella arises. 



Length 23, diam. 5.3 mm. 



Length 21.5, diam. 5.2 mm. 

 Clausilium (PI. XXI, figs. 68, 69) broad distally, irregularly 

 rounded and strongly thickened at the apex, somewhat emarginate 

 on the columellar side of the filament. 



Goto, Hizen. Types No. 82,955, A. K S. P., from No. 816 

 of Mr. Hirase's collection. The habitat "Goto, Uzen," given in 

 my preliminary note, was erroneous. 



Clearly a Stereophcedusa by its clausilium, strongly spiral inferior 

 lamella and palatal armature, yet unique in that section by the 

 beautiful plication of the right margin of the peristome. No other 

 species from Japan proper has such sculpture, a few forms of 

 Tyrannopha'diisa alone having it much less developed and confined 

 to the subcolumellar region ; but in the section Luchuphcedusa of 

 the Riukiu Islands similar interlamellar plication exists. The 

 double fold of the inferior lamella is also a rare structure, but it 

 occurs in CI. excellens Pfr., also a Riukiuan species. 



