508 PROCEEDINGS OP THE ACADEMY OF [DeC, 



whorl, which is sharply and finely striate, whorls 8 to 8J. Superior 

 lamella well developed ; subcolumellar lamella emerging. 



Length 9.5, diam. 2.3 mm. 

 8.5 " 2 " 



Heda, Kunchan. Types No. 90,021, A. N. S. P., from No. 1,843 

 of Mr. Ilirase's collection. 

 Clausilia hyperoptyx Pils. 



Specimens from Heanza-jima, Kunchan, are smaller than the types, 

 8 to 9 mm. long. They have the upper palatal plica rather long. 



A series from Sezoko-jima, Kunchan, consists in part of typical 

 hyperoptyx, in part of densely striate specimens which would be refer- 

 able to yaeyamensis, from which they differ only in the slightly finer 

 striation. 



The study of these specimens causes me to reduce C. yaeyamensis to a 

 variety of C. hyperoptyx. It differs only in the striation, and in show- 

 ing the inferior lamella somewhat more conspicuously as a thin fold, 

 in an oblique view in the mouth. In hyperoptyx this lamella recedes 

 more. The superior and spiral lamella? are weakly continuous (hyper- 

 optyx, fold above) . 



Section STEREOZAPTYX Pilsbry. 



Shell Zaptychoid, with the inferior lamella strongly spiral within, 

 thick at its base, w^iich recedes more or less ; spiral lamella weak and 

 low; lunella well developed; a nodular fulcrum present; sutural plica? 

 weak or al^sent. Clausilium well curved, wide above, strongly taper- 

 ing to the angular or narrowly rounded apex, abruptly excised on the 

 columellar side at the origin of the filament. 



This section differs from Parazaptyx and Metazaptyx in the calloused 

 columellar or inferior lamella, which in both of the others is thin and 

 high. It further differs from Parazaptyx in lacking a transverse rib 

 on the clausilium, and from Metazaptyx by the strongly tapering distal 

 end of the clausilium; that of Metazaptyx Iseing wide distally. In 

 the species now known the superior and spiral lamella? are not con- 

 tinuous. 



Clausilia entospira Pil^'. PI. XXXII, fig. 9. 



Proc. Acad. Nat. Sci. Phila., 1901, p. 64.3. 

 A figure is here given to show the internal structure, and especially 

 the fulcrum (/.), which was overlooked when I first described the 

 species. It has been found only on Tanega-shima. Additional 

 specimens received agree with the types. It is a rare snail {entospira, 

 spiral within). 



