CLASS GASTROPODA 
201 
Type in United States National Museum. Type locality, U.S.S. “Alba¬ 
tross” Station 2860, off British Columbia. 
Range. Off Queen Charlotte Islands, British Columbia, in 876 
fathoms. 
Mohnia vernalis Dali, 1913 
Plate 8, fig. 2 
Proceedings, Philadelphia Academy of Natural Sciences, 502. 
Shell small, thin, white under a light-green periostracum, of about 
seven whorls; the apex apparently blunt, but always more or less eroded; 
the nepionic whorls with a few spiral grooves, the following whorl or 
two with about sixteen rather prominent short ribs, most prominent at 
the periphery, with narrower interspaces crossed by fine spiral striae with 
wider interspaces; the ribs rapidly become obsolete and on the last three 
whorls are absent, the surface being then only marked by very arcuate 
incremental lines, the striae becoming obsolete, except on the base near 
the canal where there are a few coarse spirals; aperture short-ovate, the 
outer lip thin, sharp, the body erased, the canal short, wide, slightly re¬ 
curved, the pillar gyrate, minutely pervious; the operculum with a sub¬ 
spiral nucleus. Length of five whorls (the apex being eroded), 21; of 
last whorl, 14; maximum diameter, 10 mm. (Dali.) 
Type in United States National Museum. Type locality, off Tilla¬ 
mook Bay, Oregon, in 786 fathoms. 
Range. Tillamook Bay, Oregon, to Monterey, California, 786-881 
fathoms. 
Mohnia siphonoidea Dali, 1913 
Plate 14, fig. 7 
Proceedings, Philadelphia Academy of Natural Sciences, 502. Bulletin 112, United 
States National Museum, PI. 12, fig. 11. 
Shell solid, rotund, white, with an olivaceous polished periostracum, 
and with about six whorls; apex eroded, apparently blunt; sculpture of 
faint incremental lines and sparse zigzag obsolete ridges recalling those 
of Tritonofusus liypolispus Dali, but less distinct; whorls rather flattish, 
aperture ovate; outer lip slightly reflected, body with a thin layer of 
callus, pillar gyrate, not pervious, canal short, recurved. Operculum 
with a small subspiral nucleus. Length (eroded), 34; length of last 
whorl, 26; maximum diameter, 15 mm. (Dali.) 
Type in United States National Museum. Type locality, Bering Sea, 
off Pribilof Islands, in 987 fathoms. 
Range. Known only from type locality. 
[201 ] 
