108 PROCEEDINGS OF THE NATIONAL MUSEUM vol. loo 



is slenderer and smoother. However, many shells (of B. tenne and 

 other species) from Plover Bay tend to be large and heavy. 



The 6 specimens of Ball's variety or subspecies rhodium are all from 

 Plover Bay, eastern Siberia. Although these shells are sturdier and 

 much larger than the average B. tenue, more specimens may show 

 that they are just a Plover Bay B. tenue. Other than that of size, 

 the differences between var. rhodium and B. tenue (heaviness, prom- 

 inence of the plications and their continuance to the canal) exist in 

 varying degrees in specimens of B. tenue. 



Distribution: From Bernard Harbor (Northwest Territories), 

 Point Barrow, south to the Aleutians and east to Puget Sound; 

 eastern Siberia, and Kamchatka; the Grand Banks and Newfound- 

 land; western Greenland; Spitzbergen. It is new to Point Barrow. 



Buccinum polare Gray, 1839 



Plate 10, figures 1-4 



Buccinum polaris J. Gray, 1839, p. 128. 



Buccinum polare Martini and Chemnitz, 1883, ed. 2, pi. 9, fig. 4. 

 Buccinum orotundum Dall, 1907, p. 152. 



Buccinum pemphigus orotundum Dall, 1921, p. 99, pi. 12, fig. 9 — Oldroyd, 1927, 

 pt. 1, p. 245, pi. 14, fig. 8. 



About 9 specimens were collected: During March, April, and May 

 1950, 5 were taken at depths of 64 and 80 feet by means of baited 

 screen traps lowered to the bottom through holes in the ice; 1 (54 

 mm. high) was dredged at 80 feet (August 21, 1948); 2 (21 mm. and 

 26 mm.) at 341 feet; and 1 (30 mm.) at 438 feet. The largest speci- 

 men (57 mm. high) came from 80 feet on Mar. 20, 1950. 



Other material examined: 1 specimen from Bernard Harbor 

 (Northwest Territories), over 100 specimens from localities from 

 Point Barrow south to Nunivak Island, the PribUofs, and the Aleu- 

 tians; 20 from Plover Bay and Kamchatka; 1 from Newfoundland; 3 

 from Spitzbergen. 



Discussion: A thin, gray periostracum is present in the living 

 specimens but often begins to flake off when the shell dries. Although 

 the shell is typically thin, there are specimens in which it is fully 

 twice as thick and heavy as in others; it varies from slightly ventricose 

 to decidedly ventricose, and this same variation is evidenced in the 

 whorls. The last whorl is marked by from one to three spiral carinae 

 that usually create a keel, but not necessarily; the carina or carinae 

 may extend apically for from 3 to 5 whorls. In some shells the carinae 

 are scarcely perceptible and there is no keel or angulation. The 

 whorls are covered with spiral threads, which are crossed by the 

 incremental lines, giving a shallowly reticulate appearance. In some 

 shells these spiral threads are much coarser and the resulting sculpture 

 is sunilar to that of B. ciliatum (cf. USNM 213132, 33922, and one 



