1905.] NATURAL SCIEXCES OF PHILADELPHIA. 725 



Giiran, Taiwan. Types No. 89,945 A. X. S. Phila., from No. 1,365a 

 of Mr. Hirase's collection. 



The genus Cyathopoma is not yet .known from China. Its eastern 

 limit has hitherto been the Khasi, Naga and South Garo Hills, where 

 the species are like the Formosan in featm^es of the operculum. It 

 has not been found north of these places, nor eastward in the Dafla Hills, 

 so that its known range heretofore has been sub-Himalayan and south- 

 ward. 



In this and other known Formosan and Japanese Cyathopomas, 

 the shell has no fibrous vertically striated coating, such as is conspic- 

 uous in the Indian C. filocinctum and others. The whorls of the oper- 

 culum have no projecting lamellae. The species belong therefore to 

 the subgenus Jerdonia, as defined by Kobelt (Das Thierrcich, Cyclo- 

 phoriden, p. 219). It is clear, however, that Kobelt ignores the char- 

 acter of the operculum in his distribution of the species of Cyathopoma 

 and Jerdonia. 



C. taiivanicum is not unlike C. album Bedd., but it has more spirals, 

 and they are not so prominent in the umbilicus. 



There is a form of C. taiwanicum from Chosokei which is a little more 

 variable in sculpture than the type lot, sometimes having one or two 

 more spiral threads. 



Cyathopoma taiwanicum degeneratum n. subsp. 



At Suganiikei, Taiwan, five specimens were taken which differ 

 from C. taiwanicum by the degeneration of the spiral threads, which 

 are very weak or even almost wanting on the last whorl. T3'pes are 

 No. 89,944 A. N. S. Phila., from No. 1,365& of Mr. Hirase's collection. 



Cyathopoma micron (Pils.). 



Cyclotus micron Pils., Nautilus, 1900, p. 12. 



Taihoku (Hirase). Also found in the Ryukj'u Islands and Japan. 



Mr. Ancey has proposed a genus Nakadiella for Cyclotus (?) micron; 

 but this species differs from typical forms of Jerdonia in nothing but 

 the absence of spiral striation. There are a number of equalty smooth 

 species in Ceylon. Nakadiella may be retained as a sectional name 

 for the smooth forms, if the distinction proves to be natural; otherwise 

 it will become a synonym of Jerdonia. 



Ptychopoma (?) wilsoni (Pfr.). 



Pterocyclos wilsoni Pfr., P. Z. S., 1S6.5, p. S31, pi. 46, fig. 12. 

 Ptychopoma w., Kobelt, Das Thierreich, Cyclophoriden, p. So. 



Formosa (Swinhoe). The operculum is still unknown, and the 

 generic position therefore uncertain. 



