the samples and 41% of the specimens are in the 25-49 m 

 grouping; the 0-24 m grouping contains 16% of the samples 

 and 12% of the specimens; two other depth range groupings 

 which contain samples and specimens of this species are the 

 100-199 m and the 200-499 m groupings each of which contain 

 3% of the samples and 7 and 1%, respectively, of the speci- 

 mens (Table 214). 



Abbott (1968, 1974), Morris (1973), and Emerson et al. 

 (1976) all stated that this species is an inhabitant of mud and 

 sand bottoms. 



The majority of our samples (97%), and specimens (97%), 

 occurred in sand substrates with silty sand containing 3% for 

 each (Table 215). There are two samples containing eight 

 specimens which are unclassified with regard to sediment 

 type. 



Family TELLINIDAE 



The NEFC collection contains 67 specimens from 26 sam- 

 ples which are identified to the taxonomic level of family 

 Tellinidae (Table 5). 



Samples containing this taxon are sparsely distributed 

 along the east coast continental shelf from New York to 

 Miami, Fla. (Fig. 106; Theroux and Wigley footnote 4. table 

 190). 



The depth distribution of samples containing members of 

 the Tellinidae ranges between 4 and 1 12 m with a mean of 28 

 m. The majority of both samples and specimens are in the 0-24 

 m depth range grouping, which contains 65% of the samples 

 and 73% of the specimens; the 25-49 m and 50-99 m groupings 

 each contain 15% of the samples while the former contains 8% 

 and the latter 18% of the specimens; only one other depth 

 range grouping contains members of this taxon. the 100-199 m 

 grouping with 4% of the samples and 2% of the specimens 

 (Table 216). 



No samples containing members of this taxon occurred in 

 sand-gravel, till, or clay sediments; however, sand and sand- 

 shell substrates contained 46 and 31% of the samples, and 48 

 and 30% of the specimens, respectively; shell and silty sand 

 substrates each contained 8% of the samples and 3 and 16%, 

 respectively, for specimens; gravel and silt substrates each 

 contained 4% of the samples and 2% of the specimens (Table 

 217). 



Genus Macoma Leach 1819 



Macoma balthica (Linne 1758). Baltic macoma. Figure 58. 



The Baltic macoma is widely distributed throughout the 

 northern reaches of the Atlantic and Pacific Oceans. In the 

 Atlantic it extends from Arctic seas to Georgia while in the 

 Pacific from Arctic seas to San Diego, Calif., and Japan; it 

 also occurs in northern Europe where it is very common in 

 Norway and Sweden extending south to the Iberian Peninsula 

 (Johnson 1934; Morris 1951, 1973; La Rocque 1953; Ockel- 

 mann 1958; Tebble 1966; Abbott 1968, 1974; Emerson et al. 

 1976). 



This common and abundant bivalve of northern seas is 

 represented by 783 specimens from 45 samples in our collec- 

 tion (Table 5). 



The NEFC suite of samples ranges from the Scotian Shelf, 

 south through the Gulf of Maine onto the Middle Atlantic 



Bight continental shelf to Charleston, S.C. (Fig. 58; Theroux 

 and Wigley footnote 4, table 101). 



La Rocque (1953) considered this species to be circum- 

 boreal; Coomans (1962) placed it in the Arctic, Boreal, Virgi- 

 nian, and Caribbean zoogeographic provinces and mentioned 

 that the species, genus, and family are Celtic in Europe; 

 Dance (1974) placed it in the Boreal, Mediterranean (on the 

 Atlantic Coast), Aleutian, and Californian provinces. 



The bathymetric range of this species extends from the 

 intertidal zone to deep water (Johnson 1934; Abbott 1974). 



Our samples are from depths ranging between 1 and 403 m 

 of water with a mean of 75 m. The shallowest, the 0-24 m, 

 depth range grouping contains the largest number of samples 

 (42%) as well as specimens (77%); the next grouping contain- 

 ing significant amounts of both samples and specimens is the 

 50-99 m grouping with 24 and 16%, respectively. The 100-199 

 m grouping contains 18% of the samples but only 3% of the 

 specimens, while the 25-49 m grouping and the 200-499 m 

 grouping contain 9 and 7%, respectively, for samples, and 4 

 and 0.4%, respectively, for specimens (Table 218). 



The only sediment type in which no Macoma balthica were 

 encountered was shell. The greatest number of samples (32%) 

 occurred in silty sand while the largest number of specimens 

 occurred in sand (47%); sand contained only 23% of the 

 samples and silty sand 14% of the specimens. The finer sub- 

 strates, from silty sand through clay, contained larger 

 amounts in terms of both samples and specimens than the 

 coarser grained sediments (Table 219). One sample contain- 

 ing one specimen is unclassified with regard to sediment type. 



Macoma calcarea (Gmelin 1791). Chalky macoma. Figure 59. 



The chalky macoma is widely distributed throughout north- 

 ern Atlantic and Pacific waters. In the Atlantic it ranges from 

 Arctic seas to Long Island, N.Y., and in the Pacific from 

 Arctic seas to California and Japan; it is also widely distri- 

 buted throughout Arctic regions (Johnson 1934; La Rocque 

 1953; Ockelmann 1958; Clarke 1962; Abbott 1968, 1974). 



This common cold water species is represented in our 

 collection by 542 specimens from 75 samples (Table 5). 



Our samples range from the Scotian Shelf down to the outer 

 shores of Long Island, N.Y. (Fig. 59; Theroux and Wigley, 

 footnote 4, table 102). 



La Rocque (1953) listed the chalky macoma as circumpolar; 

 Coomans (1962) listed it as occupying the Arctic, Boreal, and 

 Virginian provinces ; Gosner ( 1 97 1 ) placed this species only in 

 the Boreal province, while Dance (1974) considered it to 

 inhabit the Arctic, Aleutian, Transatlantic, Californian, and 

 Japonic provinces; Ockelmann's (1958) view is that the 

 chalky macoma is panarctic, and that it is circumpolar with 

 Boreal outposts. 



This species enjoys a wide bathymetric range occupying 

 water depths which range from + 1 to 2,297 m (Clark 1962; 

 Abbott 1968). 



Our samples are from water depths that range from 1 to 720 

 m with a mean of 136 m. Thirty-one percent of the samples 

 and 26% of the specimens are in the 50-99 m depth range 

 grouping, while the 100-199 m grouping contains 25% of the 

 samples and 27% of the specimens. Amount of both samples 

 and specimens decreases in the depth range groupings on 

 either side of the mid and lower shelf groupings outlined 

 above (Table 220). 



40 



