80 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
whorls inflated, well-rounded, marked by strong, incised, equal and equally 
spaced spiral grooves, which are about two-thirds as wide as the spaces 
that separate them; about ten of these grooves occur between the sutures 
on the second, and thirteen on the penultimate whorl. Suture well- 
impressed. Periphery of the last whorl strongly inflated. Base rather 
short, inflated, well-rounded, very narrowly umbilicated, marked like the 
spire with spiral grooves. In addition to the spiral sculpture, the post- 
nuclear whorls are marked by rather strong, incremental lines, which 
extend over the entire surface of the post-nuclear spire. Aperture large, 
oval, slightly angulated at the posterior angle; outer lip thin, showing the 
external markings within; columella curved, slightly reflected; parietal 
wall glazed with a thick callus, which completes the peritreme; operculum 
horny, paucispiral. Length, 2.6; diameter, 2 mm. (Bartsch.) 
Type in United States National Museum, No. 160995. Type locality, 
Amchitka Island, Alaska. 
Range. Known only from type locality. 
Cingula aleutica Dali, 1886 
Plate 84, fig. 2 
Proceedings of the United States National Museum, 9:307; PI. 3, fig. 11. Ibid., 41:487; 
PI. 41, fig. 2. 
Shell elongate-ovate, light yellow. Nuclear whorls scarcely differen¬ 
tiated from the succeeding turns. Post-nuclear whorls strongly rounded, 
appressed at the summit, marked by very fine, incremental lines only. 
Suture strongly constricted. Periphery of the last whorl and the moder¬ 
ately long base well-rounded, the latter narrowly umbilicated, marked like 
the spire. Aperture large, oval, slightly expanded at the edge; posterior 
angle decidedly obtuse; peritreme complete, dark brown at the edge; outer 
lip thin; columella oblique, strongly curved; parietal wall covered with a 
thick callus, which is appressed to the succeeding whorl, completing the 
peritreme. Length, 3.2; diameter, 1.7 mm. (Bartsch.) 
Type in United States National Museum, No. 213525. Type locality, 
Unalaska, Alaska. 
Range. Pribilof Islands, to the Aleutians, to Windfall Harbor, Ad¬ 
miralty Island, Alaska. 
Cingula katherinae Bartsch, 1912 
Plate 84, fig. 3 
Proceedings of the United States National Museum, 41:488; PI. 41, fig. 3. 
Shell subglobose, dark brown. Nuclear whorls about one and one- 
quarter, well-rounded, smooth. Post-nuclear whorls strongly, roundedly 
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