1907.] NATURAL SCIENCES OF PHILADELPHIA. 511 



Clausilia inversiluna n. sp. PI. XXXIV. fiits. 43. 14. 



Shell fusiform. Ilic lower half rather obese, the spire rapidly tapering, 

 and strongly utteniuitod above. Whorls 9 to lOV, the upper ones 

 quite convex, the lower less so, last whorl tapering, laterally flattened. 

 Surface brown, shining, striatulate, the last whorl very finely and 

 densely striate. Aperture rhombic-ovate, the peristome reflexed, 

 thick, pale brownish. Superior lamella marginal, sul)vertical, becom- 

 ing very low inside, where it is w'eakly continuous with the spiral 

 lamella, which becomes high within the ventral side, and penetrates 

 past the sinulus to the middle of the left side. The inferior lamella 

 recedes deeply. Within the back it is thick and ascends vertically, 

 then bends inward, but is notcontinued on thcpenultimate whorl parallel 

 to the spiral lamella. The subcolumellar lamella emerges. The prin- 

 cipal plica is three-fourths of a whorl long, extending from near the 

 lip to a point above the sinulus. The upper palatal plica is of mod- 

 erate length, and inwardly is continuous with the slightly shorter 

 lunella, which is exactly ventral in position and descends obliquely 

 inward, to the peristome just above the superior lamella. 

 Length 11.8, diam. 2.8 mm. 

 10, " 2.8 " 

 10, " 2.6 " 

 The clausilimn (PI. XXXIV, fig. 44) is rather wide above, excised 

 at the origin of the filament, on the columellar side; it tapers distally 

 to a narrow, rounded apex, near w^hich it is concave on the palatal side. 

 Both sides are rolled back. 



Kumejima, Ryukyu. Types No. 90,045, A. N. S. P., from No. 

 1 ,359 of Mr. Hirase's collection. 



This is closely related to the preceding species (C noviluna), but it 

 differs in being larger, less strongly striate, witii the inferior lamella 

 bent less abruptly within the back; the lunella is situated more deeply, 

 and the clausiliuin is much less specialized, wanting the angular lobe 

 and notch on the palatal margin, so conspicuous in C. noviluna. The 

 l)eristome reminds one of tlie Formosan C. sheridani {inversiluna, 

 moon inverted). 



Section TIIAUMATOPTYX nov. 



Clausilia^ with discontinuous peristome, the colimicllar and parietal 

 walls covered with an adnate callus, the aperture therefore somewhat 

 Bulimoid. Inferior lamella receding, vertical below, abruptly bent 

 inward in the middle. Upper palatal plica and lunella indistinguish- 

 ahly united into one extremehj long, arcuate fold, subparallel to the 



