1913.] NATURAL SCIENCES OF PHILADELPHIA. 503 



In one specimen the space between the keels has no spiral sculpture, 

 in another there are one or two minor keels and numerous faint 

 spirals; this specimen also has a minor keel marginating the base. 

 Aperture rather small, the outer lip sharp, thin, modified by the 

 keels; inner lip erased, white; pillar gyrate, minutely pervious; canal 

 short, wide, hardly recurved. Operculum with subspiral nucleus 

 and much transparent enamel on the margin of the proximal surface. 

 Length 31; length of last whorl 20; maximum diameter 14 mm. 



Bering Sea, off Koniugi Islands, in 1,766 fathoms. 

 Mohnia buccinoides n. sp. 



Shell large, thin, with more than six whorls; white, covered with 

 an unpolished pale gray periostracum; suture not appressed; whorls 

 well rounded; spiral sculpture of a single moderately prominent 

 cord at the periphery, and numerous fine spiral striae, with somewhat 

 irregular wider interspaces; axial sculpture only of incremental 

 lines which are not conspicuous; aperture rounded-quadrate, the 

 outer lip thin, sharp, the body erased, the pillar gyrate, minutely 

 pervious; canal short, wide, recurved; operculum with a subspiral 

 nucleus. Length of (eroded) shell 38; of last whorl 27; maximum 

 diameter 19 mm. 



Off Hondo, Japan, in 905 fathoms. 



This would certainly be taken for an immature Biiccinini? if it 

 were not for the operculum. 

 Mohnia japonica n. si>. 



Shell small, polished, white under a dark green periostracum, the 

 apex eroded, but having apparentlj^ about six whorls; the first intact 

 whorl shows faint indications of obsolete ribbing, the later whorls 

 are smooth except for faint incremental lines and obscure, almost 

 microscopic spiral stride; on the base there are the usual spiral threads 

 near the canal. Aperture elongate-ovate, outer lip thin, sharp; 

 body erased, canal short, wide, recurved, axis gyrate, not pervious. 

 Length of shell (eroded) 19; of last whorl 13; maximum diameter 

 8.5 mm. 



Off Sado Island, Japan Sea, in 225 fathoms. 

 Mohnia kurilana n. sj. 



Shell small, very delicate, with a blunt nucleus and six and a half 

 well-rounded whorls; whitish under a thin olivaceous velvety 

 periostracum; nucleus blunt, axially minutely sharply ribbed; the 

 next whorl with many minute riblets is cancellated by. revolving 

 threads; the subsequent whorls have six or seven nearly uniform 

 33 



