CLASS GASTROPODA 
133 
almost straight, without callus; nucleus smooth, white, pointed, drawn 
out; sculpture consisting of longitudinal ribs thirteen or fourteen on the 
last whorl, obsolete on the lower third of the whorl and not extending 
to the suture, below which is a smooth band only marked by oblique lines 
of growth; ribs slightly nodulous at their posterior terminations (where 
they are united by a slight carina) strong on the upper whorls, slightly 
flexuous on the convexity of the whorl. Whorl below the carina marked 
by very faint grooves close together and passing over the ribs, stronger 
at the anterior end of the last whorl. Long., .68; lat., .24 in. (Dali.) 
Type in United States National Museum. Type locality, Unga Island, 
of the Shumagin group, in the North Harbor. 
Range. Cape Sabine, Arctic Ocean, to Straits of Juan de Fuca. 
Mangilia carlottae Dali, 1919 
Plate 2, fig. 24 
Proceedings of the United States National Museum , 56 :65; PI. 21, figs. 9, 12. 
Shell small, thin, snow-white, with a swollen smooth nucleus of two 
whorls and six subsequent whorls; suture distinct, not appressed; the 
anal fasciole sloping forward flatly to the shoulder of the whorl with 
only arcuate incremental lines for sculpture; axial sculpture of (on the 
last whorl, about 20) obliquely protractive short ribs, strongest at the 
shoulder and on the last whorl stopping abruptly near the periphery; spiral 
sculpture hardly perceptible; on the base are a few distant obsolete threads 
and faint microscopic striae; these vary in strength in different specimens; 
anal sulcus rounded, wide, and shallow; outer lip thin, sharp, arcuately 
produced; aperture narrowly ovate, inner lip erased; pillar and canal 
short, the latter wide and hardly differentiated. Height of shell, 9; of 
last whorl, 5.5; diameter, 4 mm. (Dali.) 
Type in United States National Museum No. 210724. Type locality, 
Station 2860, off Queen Charlotte Islands, British Columbia. 
Range. Off Queen Charlotte Islands, British Columbia, in 876 
fathoms. 
Mangilia nunivakensis Dali, 1919 
Proceedings of the United States National Museum, 56:67; PI. 23, fig. 2. 
Shell thin, rather large, whitish, acute, elevated, of about seven whorls, 
the nucleus eroded, suture distinct, the anal fasciole hardly constricted, 
concavely wrinkled; axial sculpture of (on the penultimate whorl, about 
18) protractive rather feeble, rounded ribs, with subequal interspaces, 
becoming obsolete on the base; spiral sculpture practically none; aperture 
[133] 
