MARINE MOLLUSKS — MACGINITIE 87 



Family Triphoridae 



Genus Triphora Blainville, 1828 

 Triphora perversa ( Linnaeu8, 1758) 



Plate 3, figure 6 



Trochus perversus Linnaeus, 1758, p. 760. 

 ICerithium perversum Bruguifere, 1792, p. 496. 



One immature specimen was dredged at 341 feet. Including the 

 nucleus, it has 8 whorls and is 2.5 mm. long by 1.3 mm. in diameter; 

 it is reddish brown in color, with lighter nodules. 



Other material examined: About 55 specimens from the British 

 Isles, 2 from Norway, and 13 from Tangier Bay, Sicily, and the Aegean. 



Discussion: This species is new to Arctic waters. The only other 

 specimens collected north of the British Isles are those from Lofoten, 

 Norway. Because of its small size and inconspicuous coloring, it has 

 doubtless been overlooked in collections. 



Distribution: Point Barrow, Alaska; Dr. Thorson (personal com- 

 munication) gives the Atlantic range as coast of Norway from Lofoten 

 south, western Sweden, Denmark, the Shetlands, Orkney Islands, 

 Great Britain, Ireland, coast of Europe to Madeira and the Canar}' 

 Islands; also covers the Mediterranean. 



Family Crepidulidae 

 Genus Crepidula Lamarck, 1799 



Crepidula grandis'Middendorff, 1849 



Plate 1, figure 11; Plate 5, figure 7 



Crepidula grandis Middendorflf, 1849b, p. 18; 1849c, p. 101, pi. 11, figs. 8-10; 

 1849d, p. 429, pi. 11, figs. 8-10.— Kira, 1954, p. 28, pi. 14, fig. 3. 



Fourteen live specimens and 2 shells were collected at depths of 120 

 to 453 feet. In August 1949 one live specimen with a shell 10 mm. long 

 was washed ashore during a storm. Its shell was covered Avith the soft, 

 encrusting bryozoan Alcyonidium polyoum (Hassall) . This species is 

 ordinarily attached to rocks but one specimen 6.5 mm. long was found 

 among a foliaceous bryozoan at 120 feet (Sept. 15, 1948). Although 

 C. grandis is the largest Crepidula known, the ones from Point Barrow 

 were small, ranging from 4.7 to 32.0 mm. in length, only three exceed- 

 ing 20.0 mm. 



Other material examined: One dead shell from Icy Cape, 2 from 

 Point Franklin, 1 small living one from "north of Bering Strait." 

 and about 100 specimens from Kamchatka, Plover Bay, the Pribilofs, 

 and other localities south and east to Sitka, Alaska. 



