collection by 1 . 1 32 specimens from 1 27 samples each of which 

 represent approximately 1% of their respective group (Table 

 5). 



Our samples are from the periphery of the Gulf of Maine 

 and Georges Bank, and extend onto the Southern New Eng- 

 land shelf and slope region with two isolated samples on the 

 continental shelf off New York and Atlantic City, N.J. (Fig. 

 62; Theroux and Wigley footnote 4, table 108). 



This species occupies the Arctic, Boreal, Virginian, and 

 Carolinian zoogeographic provinces in the western Atlantic. 

 and the Celtic province in Europe (Coomans 1962); Gosner 

 (1971) listed it as occurring in the Boreal and Virginian pro- 

 vinces, and Dance (1974) placed it in the Boreal, Transatlan- 

 tic, Aleutian, and Japonic provinces. 



This species ranges from slightly below low tide level out to 

 approximately 81 m depth (Gosner 1971; Porter 1974). 



The samples in the NEFC collection range in depth be- 

 tween 13 and 256 m with a mean of 77 m. The majority of our 

 samples are in the 50-99 m depth range grouping which con- 

 tains 55% of the samples and 27% of the specimens; the 

 largest number of specimens (58%). however, are in the 25-49 

 m grouping which contains 23% of the samples. Seventeen 

 percent of the samples and 10% of the specimens, are in the 

 100-199 m depth range grouping, while the 200-499 m grouping 

 contains 2% of the samples and 5% of the specimens; the 

 smallest amount of each is in the 0-24 m depth range grouping 

 which contains 2% of the samples and 0.3% of the specimens 

 (Table 96). 



Morris (1951) reported this species as an inhabitant of rocky 

 bottoms. 



Our samples occupied all sediment types considered in this 

 report. The majority of samples occurred in sand which con- 

 tained 34% of the former and 10% of the specimens. The 

 largest number of specimens (54%) were in sand-shell bot- 

 toms which contained only 6% of the samples: sand-gravel 

 substrates contained 24% of each, samples and specimens; 

 significantly smaller amounts occurred in gravel, till, shell, 

 sand-shell, silty sand, silt, and clay sediments (Table 97). 

 There are 29 samples containing 179 specimens which are 

 unclassified with regard to sediment type. 



Genus Musculus Bolten 1798 



Musculns corrugatus (Stimpson 1851). Wrinkled musculus. 

 Figure 64. 



The wrinkled musculus occurs in both the North Atlantic 

 and North Pacific Oceans. In the Atlantic it ranges from 

 Arctic seas and northern Europe to off North Carolina and is 

 considered to be circumpolar, while in the Pacific it ranges 

 from Alaska to Puget Sound (Johnson 1934; Ockelmann 1958; 

 Abbott 1974). 



This small mussel is represented in the NEFC collection by 

 88 specimens from 11 samples (Table 5). 



Our samples are confined to the Georges Bank-Gulf of 

 Maine and Nantucket Shoals regions (Fig. 64: Theroux and 

 Wigley footnote 4, table 1121. 



It is an inhabitant of the Arctic. Boreal, and Virginian 

 provinces (Coomans 1962); however. Gosner(1971) placed it 

 in the Boreal and Virginian provinces. 



The range of depth in which this species is found is from 2 to 

 183 m (Johnson 1934: Abbott 1974). 



The NEFC samples are from water depths ranging between 

 35 and 102 m with a mean of 77 m. The majority of samples 

 (73%) and specimens (75%) are in the 50-99 m depth range 

 grouping: 18%' of the samples and 2% of the specimens are in 

 the 25-49 m grouping, and 9% of the samples, but 23% of the 

 specimens are in the 100-199 m depth range grouping (Table 

 98). 



The majority of both samples and specimens occurred in 

 sand-gravel substrates where 40% of the samples and 61% of 

 the specimens were found; till substrates contained 30% of 

 the samples and 33% of the specimens, while shell contained 

 10% of the samples and 4% of the specimens: sand substrates 

 yielded 20% of the samples and 2% of the specimens (Table 

 99). There is one sample containing one specimen which is 

 unclassified with regard to sediment type. 



Musculus discors I Linne 1767). Discord musculus. Figure 65. 



This mussel occurs in both the Atlantic and Pacific Oceans. 

 In the Atlantic it ranges from Labrador and Arctic seas to 

 Long Island and is considered to be circumpolar; in the Paci- 

 fic it ranges from Arctic seas to Puget Sound and to Japan ; it is 

 also found in western Europe, in the Mediterranean, and in 

 northern Eurasia (Johnson 1934; Ockelmann 1958; Clarke 

 1962; Tebble 1966; Morris 1973; Abbott 1974). 



This is a commonly dredged deep water mussel which is 

 represented in our collection by 457 specimens from 80 sam- 

 ples (Table 5). 



Our samples are from the periphery of the Gulf of Maine 

 and the Northeast Peak and Southwestern Part of Georges 

 Bank (Fig. 65; Theroux and Wigley footnote 4, table 113). 



This species is Arctic, Boreal, Virginian, and Celtic in 

 zoogeographic distribution (Coomans 1962); Gosner (1971) 

 placed it in the Virginian province; Dance (1974) placed it in 

 the Boreal, Mediterranean, Transatlantic, Arctic, Indo- 

 Pacific, and Japonic provinces. 



The depth range for this species is from to 3,267 m (Clarke 

 1962). 



Our samples are from depths which range between 29 and 

 198 m with a mean of 81 m. Fifty-nine percent of the samples 

 and 40% of the specimens are in the 50-99 m depth range 

 grouping; 18% of the samples and 54% of the specimens are in 

 the 25-49 m grouping, and 24% of the samples and 6% of the 

 specimens are in the 100-199 m grouping (Table 100). 



The only sediment type in which this species was not found 

 was silt. The majority of both samples and specimens 42 and 

 82%, respectively, occurred in sand-gravel; gravel substrates 

 contained 21% of the samples and 5% of the specimens; till 

 substrates contained 16% of the samples and 4% of the spe- 

 cimens; shell contained 2% of the samples and 4% of the 

 specimens; sand-shell contained 4% of the samples, and < 1% 

 of the specimens; sand contained 9% of the samples, 2% of the 

 specimens; while silty sand had 2% and < 1%, respectively; 

 clay 5% of the samples and 1% of the specimens (Table 101). 

 There are 23 samples containing 40 specimens which are not 

 classified with regard to sediment type. 



Musculus niger (Gray 1824). Black musculus. Figure 66. 



The black musculus is found in both the North Atlantic and 

 North Pacific Ocean. In the Atlantic it ranges from Arctic seas 

 and Greenland to North Carolina, and in the Pacific from 



18 



