MARINE MOLLUSKS — MACGINITIE 165 



highly variable characters as color and the relative coarseness of con- 

 centric ribs. Both Lamy (1919) and Dall (1903a) made revisions 

 of this genus, but Lamy did not have access to many of the Pacific 

 species, and Dali, like the present writer, did not have access to 

 many European species; and by the time their revisions were made 

 the species were so hopelessly confused in the literature that the 

 only way to straighten them out would be to see the specimens on 

 which the various papers were based. Jensen's work (1912) on several 

 species was an excellent contribution. 



Astarte borealis Scliuinaclier, 1817 



Plate 22, figuees 1-6 



Astarte borealis Schumacher, 1817, p. 47, pi. 17, fig. 1. — Dall, 1903a, pp. 941, 

 944.— Jensen, 1912, p. 92, pi. 4, figs, la-f.— Soot-Ryen, 1939, p. 10, pi. 1, 

 figs. 1-3.— Morris, 1952, p. 33, pi. 8, fig. 21.— Abbott, 1954, p. 375, pi. 28q.— 

 Kira, 1954, p. 105, pi. 52, fig. 22. 



Astarte arctica Moller, 1842a, p. 20; 1842b, p. 93. 



Astarte semisulcata Moller, 1842a, p. 19; 1842b, p. 92. 



Astarte richardsoni Reeve, 1855, p. 397, pi. 33, figs. 7a, b. 



Approximately 40 specimens (including empty shells) were dredged. 

 About one half of this number came from Eluitkak Pass and at least 

 half of them were empty shells. The remaining specunens and shells 

 came from 11 stations ranging in depth from 80 feet (Sept. 8, 1948) 

 to 438 feet. With the exception of the station at 295 feet, with 5 

 specunens, no station other than Eluitkak Pass yielded more than 

 one or two. The largest living specimen (54 mm. long by 43 mm. 

 high by 20.4 m.m. in breadth) came from Eluitkak Pass; two other 

 shells from Eluitkak Pass and 1 from 295 feet exceed 50 mm. in length, 

 and at least 22 others exceed 40 mm. in length. The 3 smallest 

 specimens are: 1 (14.5 by 11.5 b}^ 5.4 mm.) from 118 feet; 1 (13 by 

 11 by 10 mm.) from 341 feet; and 1 (17.5 by 13 by 6 mm.) from 295 

 feet. The complete absence of very small specimens is worthy of note. 



Empty shells were usually filled with mud and were so tightly 

 closed that it was impossible to distinguish empty from living shells 

 without opening them. Since the umbos of living shells were often 

 as worn and eroded as those of dead shells, the external appearance 

 was no criterion. 



Other material examined: Over 100 specimens from the follow- 

 ing localities: Franklin Bay, Icy Cape, Plover Bay, Bering Sea, and 

 the Kudobin Islands; Wellington Channel, Cumberland Gulf, the 

 Grand Banks, and Labrador; and Novaya Zemlya. 



Discussion: The Point Barrow shells vary in color from light 

 brov/n to black, sometimes with combinations of the tv\^o colors in the 

 same shell. Some, even living ones, have a rustlike deposit or con- 



