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PROCEEDINGS OF THE NATIONAL MUSEUM 



Table 6. — Proportionate lengths and heights of Macoma moesta and M. "krausei" 



(Key: H, height at umbo; H', height at highest point of shell; L, length. Measurements in millimeters, 



ratios in percent) 



The longer length of M. krausei to its height in comparison with 

 that of M. moesta is demonstrated in table 6. However, it is highly 

 probable that Dall's specimens of M. krausei are simply extreme 

 variants and that the greater length of these specimens comes within 

 the normal limits of variation of M. moesta. 



Distribution: Point Barrow, Alaska, Nunivak Island, the Aleu- 

 tians, coasts of Washington, Oregon, and Monterey Bay, Calif., also 

 Kamchatka; W. K. Ockelmann (personal communication) gives the 

 Atlantic range as eastern and western Greenland, Baffin Land, Spitz- 

 bergen, Novaya Zemlya, and the Kara Sea; and Jensen (1905) adds 

 the Tschuktscher Peninsula and the Siberian-Arctic Sea. 



Suborder Asthenodonta 



Family Myacidae 



Genus Mya Linnaeus, 1758 



Mya truncata Linnaeus, 1758 

 And var. uddevallensis Forbes 



Plate 25, figures 1-3 



Mya truncata Linnaeus, 1758, ed. 10, p. 670. — Oldroyd, 1924, p. 197, pi. 10, 

 fig. 4.— Foster, 1946, p. 30, pis. 17-19.— Morris, 1951, p. 89, pi. 22, fig. 8; 

 1952, p. 58, pi. 16, fig. 5.— Abbott, 1954, p. 455, pi. 32v. 



Mya truncata var. uddevallensis Forbes, 1846, p. 407. — Grant and Gale, 1931, 

 p. 415. 



Mya truncata var. abhreviata Jeffreys, 1865b, p. 67. 



Approximately 25 specimens were collected: 12 specimens, usually 

 with the animal intact and sometim.es still living, and 4 valves washed 

 ashore between Aug. 21 and Sept. 28, 1949; 2 specimens (55 and 55.3 

 mm.) and 1 valve (57 mm.) were taken at Eluitkak Pass; 1 juvenile 

 (probably of true M. truncata) was collected at 10 feet on Oct. 14, 

 1949; 4 (from 6 to 8.5 mm.) came from 477 feet; 1 (19.5 mm.) came 



