1902.] NATURAL SCIENCES OF PHILADELPHIA. 117 



usually occur in the next species, though specimens " often present 

 hammered -like sculpture on the surface," hence the name 

 malleaius. 



Mr. Iwakawa has traced this species from the Province Mutsu, at 

 the north end of Nippon, to the middle Riukiu Islands. Mr. 

 Hirase sends specimens from the islands also. Fig. 6 represents a 

 specimen from Kagoshima, Satsuma. Fig. 7 is from a very smooth 

 and glossy shell from Okinawa. 



This species is more globose than the Chinese V. stelmaphora, 

 the tube enlarging more rapidly, producing a lower spire and 

 larger aperture. 



Paludina Iceta v. Martens (Malak. Bldtt., VII, 45), described 

 from a specimen or specimens collected by Siebold, and not figured, 

 is a glossy form with some puncture-lines, as in the smooth form of 

 V. malleatus. The type has 6 whorls, and measures alt. 23, diam. 

 21 mm. The last whorl is distinctly angular. I think this is 

 likely to prove to be a form of V. malleatus. If so, the name 

 has priority. 



Viviparus japonicus (v. Martens). PI. IX, fig. 1. 



Paludina japonica v. Mart., Malakozoologische Blatter, VII, 1860, 



p. 44. Reeve, Conch. Icon., fig. 13. Kobelt, t. c., p. 120, PI. 11, 



fig. 1. 



Paludina oxytropis var. japonica Iwakawa, t. c., p. 88, PI. 5, fig. 17. 

 Paludina oxytropis var. sclateri Iwakawa, t. c., p. 89, PL 5, fig. 14. 



Large, pyramidal, dark olive-green and glossy. The earlier 

 whorls are encircled by two keels, later becoming mere angles, and 

 then usually disappearing on the last whorl or two. There may also 

 be some oblique malleation in places. The last whorl is obscurely 

 angular, the angle darker. There are no puncture -lines, as in 

 V. malleatus, though there are fine, subobsolete spiral striae. The 

 specimen figured is from Omaki, Yamashiro. The type locality is 

 not known, the specimens brought home by Siebold being merely 

 labeled Japan. 



Viviparus japonicus var. iwakawa nov. PI. IX, fig. 3. 



Paludina oxytropis Bens., Kobelt, t. c., p. 123, PI. 11, figs. 6, Qa, 



(exclusive of synonymy). 

 P. oxytropis Bens., Iwakawa, t. c., p. 88, PI. 5, figs. 12, 13. Not 



Paludina oxytropis Benson, an Indian species belonging to an 



appreciably different group ! 



Differing from V. japonicus chiefly in the persistence in adult 

 shells of the keel at the periphery, giving the shell ' ' the shape of a 



