88 PROCEEDINGS OF THE NATIONAL MUSEUM vol. lo© 



Discussion: The shell is white, both inside and out, and older 

 specimens become rough and coarse. It is covered by a tan perio- 

 stracum that is usually worn off in a large area around the apex and is 

 often folded and overlapped around the periphery. There are varia- 

 tions in the relation of height to width: some are high and narrow, 

 others flat and wide, with all gradations between. 



Distribution: Point Barrow, south and east to Sitka. Also 

 Kamchatka, It is new to Point Barrow. 



Family Trichotropidae 



Genus Trichotropis Broderip and Sowerby, 1829 



Trichotropis bicarinata (Sowerby, 1825) 



Turbo hicarinatus Sowerby, 1825, appendix, p. 12. — Broderip and Sowerby, 1829, 



p. 374, Turbo, pi. 9, figs. 4-8. 

 Trichotropis bicarinata Hirase, 1951, pi. 91, fig. 14. — Abbott, 1954, p. 168, pi. 



24a.— Kira, 1954, p. 27, pi. 13, fig. 13. 



Six living specimens and 3 dead shells were collected: 1 (10.8 mm. in 

 diameter) from 130 feet; 2 dead shells (33.6 mm. and 37.5 mm.) from 

 420 feet; 2 (9.8 and 11.7 mm.) from 438 feet;2 living (9.5 and 32.2 mm., 

 and 1 dead (42.5 mm.) from 453 feet; and 1 living (4.8 mm. in diameter) 

 from 477 feet. 



Other material examined: Numerous specimens from the Sea 

 Horse Islands, Cape Sabine, Bering Strait, Plover Bay, St. Paul 

 Island, Nunivak Island, and 2 large specimens from deep water off 

 Nemuro, Yesso, Japan. 



Discussion: The specimens from Point Barrow present no great 

 differences from the typical. There were none of Dall's variety alta 

 (which is merely a more slender form), nor of his variety spectabilis 

 (which has unusually prominent processes of periostracum extending 

 from the keels). 



Distribution: Point Barrow south to Nunivak Island, and northern 

 Japan; the east coast of North America. It has been reported from 

 Greenland and Iceland, but Thorson (1944) does not hst it. It has 

 not been reported previously from north of Icy Cape in the Alas- 

 kan Arctic. 



Trichotropis borealis Broderip and Sowerby, 1829 



Trichotropis borealis Broderip and Sowerby, 1829, p. 375. — Morris, 1947, p. 117, 

 pi. 39, fig. 17; 1951, p. 153, pi. 39, fig. 17; 1952, p. 103, pi. 26, fig. 10.— 

 Abbott, 1954, p. 167, pi. 24d. 



Only 2 specimens of this species were taken, both living: 1 (14.0 high 

 by 10.3 mm. in diameter) from 130 feet (Sept. 15, 1948) ; and 1 (16.3 by 

 11.5 mm.) from 130 feet (Aug. 9, 1949). 



