1904.1 



NATURAL SCIENCES OF PHILADELPHIA. 825 



arc from Tancga-shima and Yaku-shima, bvit the group extends south 

 to Tokuno-shima. Type C. pinto. 



The following species belong here : 



C. pinto PlIs. Tanega-shima, Osumi. 



C. ptychocyma Pils. Tancga-shima, Osumi. 



C. ptychocyma ijakushimce Pils. Yakushima, Osumi. 



C. asperata Pils. Shimo-Koshikijima, Satsuma. 



C. caloptyx Pils. Yakushima, Osumi. 



C. agna Pils. Yakushima, Osumi. 



C. purissima Pils. Miyakejima, Izu. 



C. hyperaptyx Pils. Tokunoshima, Osumi. 



C. munus Pils. Oshima, Osumi. 



Key to Species of Hemizaptyx. 

 I. — Clausilium rounded at the distal end. 



a- — Upper palatal plica extremely short or apparently absent, 

 merely an enlargement of the upper end of the lunclla. 

 6. — Solid and strong, nearly smooth; lip very thick, hardly 

 free above; superior lamella contiguous to the spiral; 

 subcolumellar lamella emerging. Tancgashima, 



C. pinto. 



b^. — Extremely solid and strong; almost smooth, the last whorl 



coarsely wrinkled behind the lip; superior lamella sep- 



rated from spiral ; subcolumellar lamella emerging 



or immersed. Tancgashima and Yakushima, 



C. ptychocyma. 



b^. — Moderately strong; very finely striate, the last whorl with 



spaced riblets behind; superior lamella continuous with 



the spiral; subcolumellar lamella immersed. Shimo- 



Koshikijima, Satsuma, C. asperata. 



a*. — Upper palatal plica short but distinctly developed. 



b. — Solid and strong; surface sculptured with strong straight 

 ribs; length 7 to 8 mm. Yakushima, . C. caloptyx. 

 b^. — Surface smooth, brilliantly glossy; more or less transpar- 

 ent. 

 c. — Whorls 6J to 8; shell stoutly fusiform, the diameter 

 contained 3^ to 4 times in the length; subcolumellar 

 lamella weakly emerging. Yakujima, . C. agna. 

 c^.- — Whorls 10; shell slenderly fusiform, the diameter con- 

 tained 5 times in the length; subcolumellar lamella 

 immersed. ]\Iiyakejima, Izu, . . C. purissima. 

 n. — Clausilium angular or acuminate at the distal end; superior 

 lamella continuous with the spiral ; upper palatal plica rather 

 short, scarcely connected with the slightly curved lunella. 

 a. — Shell dark, glossy and rather thin, 10 to 11 mm. long; about 

 7^ whorls; sides of the clausilium strongly reflexed. 



Tokunoshima, C. hyperaptyx. 



r).3 



