200 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
other axial sculpture of obscurely channeled grooves which become wider 
with age and on the penultimate whorl are about fourteen in number; 
on the last whorl they are coarsest on the base, but nowhere sharp or 
clean cut; the whole surface is covered with a dark olive periostracum, 
under which the shell is white; aperture ovate, the body erased white, 
the pillar gyrate but not pervious, the outer lip thin, sharp; the canal 
rather wide and strongly recurved. The nucleus is not preserved on 
any of the specimens. The operculum is dark horn color and forms about 
one whorl. Length of type specimen (about five whorls, 36.5; of last 
whorl, 25; maximum diameter, 15 mm. (Dali.) 
Type in United States National Museum. Type locality, Bering 
Sea, in 987 fathoms, off Pribilof Islands. 
Range. Off Pribilof Islands, in 987-1,401 fathoms. 
Mohnia corbis Dali, 1913 
Proceedings, Philadelphia Academy of Natural Sciences, 501. Bulletin 112, United 
States National Museum; PI. 12, fig. 10. 
Shell with the apex eroded and about five rounded whorls remaining; 
white, covered with an olivaceous yellow periostracum; suture appressed; 
axial sculpture of numerous, rather irregular, prominent incremental 
lines; spiral sculpture of, between the sutures, about seven cord-like 
ridges, which on the last whorl become flatter and strap-like; the inter¬ 
spaces are irregular, but usually wider; between the cord at the shoulder 
and the suture behind there is a flattish space with four or five obsolete 
finer spirals; contrary to custom, the base of the last whorl and canal 
have no spiral sculpture; aperture short-oval, the outer lip thin, short, 
the body erased white, the pillar gyrate and minutely pervious ^ canal 
very short, wide, and slightly recurved; operculum with a small subspiral 
nucleus. Length of shell, 31; of last whorl, 20; maximum diameter, 
14 mm. (Dali.) 
Type in United States National Museum. Type locality, Bering Sea, 
off the Pribilof Islands, in 1,771 fathoms. 
Range. Off the Pribilof Islands, 1,771 fathoms. 
Mohnia frielei Dali, 1891 
Plate 25, fig. 8; Plate 15, fig. 5 
Proceedings of the United States National Museum, 14:186; 17; PI. 29, fig. 8, 1894. 
Shell small, solid, six-whorled with short canal; white, covered with 
a dull-green epidermis; upper whorls with numerous fine transverse ribs, 
last whorl smooth, no spiral sculpture. Length, 16; breadth, 7.5; aper¬ 
ture and canal, 8 mm. (Dali.) 
[200 ] 
