830 PROCEEDINGS OF THE ACADEMY OF [Dec., 



and a little curved within, not continued parallel to the spiral lamella, 

 but a very small inserted lamella (1. inserta) appears near the end of 

 the spiral lamella. Subcolumellar lamella wholly immersed. There 

 is a fulcrum and a parallel lamella. Principal plica short, dorsal 

 and lateral, visible in the mouth. Upper palatal plica short, joined 

 in the middle to the long lunella, which is straight above, curved in- 

 ward below. A single sutural plica is developed, with the trace of a 

 second upper one. 



Length 10, diam. 2.2 mm. 



Length 9, diam. 2.3 mm. 



Clausilium (PL LVI, figs. 72, 73) parallel-sided, rounded at the apex, 

 deeply excised on the columellar side of the filament. 



Okinoerabushima, Osumi. Types No. 87,613, A. N. S. P., from No. 

 1,253 of Mr. Hirase's collection. 



This species resembles C. hirasei, but differs in the decidedly stronger 

 striation of the last whorl behind the lip, the wider peristome, immersed 

 subcolumellar lamella, the more convex whorls and the poorer develop- 

 ment of sutural plicae. It is nearly opaque. As in C. hirasei, the 

 inferior lamella is interrupted within. The palatal side of the filament 

 is less dilated above than in C. hirasei. The specimen figured has a 

 thicker peristome than most of those sent. The figure is too distinctly 

 streaked. 



Clausilia hyperoptyx Pilsbry. PL LVI, figs. 76, 77, 78, 79. 



Proc. Acad. Nat. Sci. Phila., 1900, pp. 446, 472; 1901, pp. 423. 



The statement in the original description that the "upper palatal 

 plica is very short" was an error, which the figure (PL 14, fig. 12) 

 corrects. The upper palatal plica is rather long, united in the middle 

 with the lunella. The superior lamella is higher, better developed than 

 in C. hirasei and C. kikaiensis. The tapering spire is distinctly attenu- 

 ated above, but the apex is larger than in the related species ; and the 

 striation is better developed than in C. hirasei or C. kikaiensis. It is 

 known only from Great Ryukyu Island (Okinawa); the specimens 

 reported from Yaeyama prove to be specifically different. 



Length 9 to 10, diam. 2 mm. 



The clausilium (PL LVI, figs. 76, 77) is rather wide, rounded distally. 

 It is wider than that of hirasei, kikaiensis or sarissa. 



Clausilia hyperoptyx yoronjimana n. subsp. 



The superior and spiral lamellae are more or less completely discon- 

 nected, and the lunella joins the middle of the short upper palatal plica, 

 as in C. hyperoptyx; but the shell is perceptibly wider, and the last 



