NO. 1871. 



WEST AMERICAN CIXGULA—BART8CH. 



487 



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 10 of these grooves occur 

 between the sutures on the second, and 13 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 ^^Hth spiral grooves. In addition to the spiral 

 sculpture the post-nuclear whorls are marked by rather strong, incre- 

 mental lines, wliich extend over the entire surface of the post-nuclear 

 spire. Aperture large, oval, slightly angidated at the posterior angle; 

 outer lip thin, sho^\^ng the external markings A^^thin; columella 

 Qurved, slightly reflected; parietal wall glazed "with a tliick callus, 

 which completes the peritreme; operculum horny, pauci-spiral. 



The type (Cat. No. 160995, U.S.N.M.) has two and one-haJf post- 

 nuclear whorls and measures: Length 2.6 mm, diameter 2 mm. It 

 was coUected by Doctor Dall at Amchitka Island, Alaska. 



CINGITLA ALEUTICA Dall. 



Plate 41, figure 2. 



Onoba aleutica Dall, Proc. U. S. Nat. Mus., vol. 9, 1886, p. 307, pi. 3, fig. 11. 



SheU elongate-ovate, light 3^ellow. Nuclear whorls scarcely differ- 

 entiated 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 moderately long base well rounded, the latter narrowly 

 umbihcated, 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 obhque, 

 strongly curved; parietal wall covered with a thick caUus, which is 

 appressed to the succeeding whorl, completing the peritreme. 



The type (Csit. No. 213525, U.S.N.M.) has five and one-half post- 

 nuclear whorls and measures: Length 3.2 mm., diameter 1.7 mm. 



Specimens examined. 



Cata- 

 logue 

 No. 



Locality. 



Number 

 of speci- 

 mens. 



1 213525 

 151618 

 1G0981 

 101089 

 160871 

 180354 

 204022 

 203702 

 213526 



Unalaska, Alaska 



St. Pauls Island, Alaska 



St. Paul, Pribilofl" Islands, Alaska (0 to 9 fathoms) 



Constantine Harlwr, Amchitka Island, Aleutians, Alaska. 



Popofi Strait, Shumagins, Alaska (6 fathoms) 



Cooks Inlet, near Soldovia, Alaska 



Windfall Harbor, Admiralty Island, Alaska 



do <: 



Kyska Harbor, Aleutians, Alaska (beach, low water) 



1 

 1 

 1 

 5 

 1 

 1 

 1 

 126 



I Figured type. 



