46 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 95 



marked by incremental lines which gradually develop into ribs on the 

 later whorls. Postnuclear whorls inflated, strongly rounded, marked 

 by very strong, slightly retractively slanting, axial ribs, of which, in 

 the specimen figured, there are 12 on the last whorl behind the varix, 

 13 on the penultimate, 12 on the next 3 whorls, 14 on the sixth from 

 the last, and 8 plus on the seventh from the last whorl. The broad 

 intercostal spaces and the ribs are marked by heavy wavy incremental 

 lines. It is the regularity of these waves that suggests spiral sculpture. 

 Suture strongly constricted. Periphery strongly rounded. Base 

 narrowly umbilicated, marked by the continuation of the axial ribs 

 and incremental lines which extend onto the umbilicus. There is a 

 heavy varix behind the peristome on the outer lip. The aperture is 

 broadly ovate. Peristome is thickened and reflected, dark-edged, ad- 

 nate to the preceding turn at the parietal wall. The operculum is 



typically oncomelanid. The radula has the formula : 2-1-3: 



7:5- 



The specimen described and figured, U.S.N.M. no. 420956, was 

 collected by Dr. H. E. Meleney from ponds just north of the Yangtze 

 River, a few miles east of Hankow, Hupeh Province, China. It has 

 7 whorls remaining, and measures : Height 9.9 mm ; diameter 4.1 mm. 



Ten specimens from this lot yield the following measurements : 



Forty additional specimens from the same locality give the follow- 

 ing measurements : 



