The single sample containing this species in our collection 

 is from off Key West, Fla. (Fig. 70, Theroux and Wigley 

 footnote 4, table 121). 



Coomans (1962) listed this species from the Virginian, 

 Carolinian, and Caribbean zoogeographical provinces. 



The depth range for this species is 33 to 641 m (Abbott 

 1974). 



Our sample is from a depth of 220 m. This depth places it in 

 the 200-499 m depth range grouping. The sample was obtained 

 from a silty sand substratum. 



Genus Papyridea Swainson 1840 



Papyridea semisulcata (Gray 1825). Frilled paper cockle. Figure 

 84. 



The frilled paper cockle occurs at Bermuda and is also 

 distributed from southern Florida to Brazil (Johnson 1934; 

 Abbott 1974). 



Papyridea semisulcata is an uncommon warm water 

 bivalve of which there are three specimens from two samples 

 in our collection (Table 5). 



The two samples in the NEFC collection are from the 

 continental shelf north of Miami, Fla. (Fig. 84; Theroux and 

 Wigley footnote 4, table 143). 



According to Abbott (1974), depths at which this species 

 may be found range from low tide line to approximately 73 m. 



Our samples are from 28 and 36 m of water. This depth 

 range places both samples and their three specimens in the 

 25-49 m depth range grouping. 



Our samples were obtained in a sand substratum. 



Family MACTRIDAE 

 Genus Mulinia Gray 1837 



Mulinia lateralis (Say 1822). Dwarf surf clam. Figure 63. 



The dwarf surf clam is distributed from the Gulf of St. 

 Lawrence to northern Florida, it extends into Texas, and is 

 also present in the West Indies (Johnson 1934; Morris 1951, 

 1973; La Rocque 1953; Ockelmann 1958; Abbott 1974; Emer- 

 son et al. 1976). 



This is a very abundant east coast bivalve species of which 

 there are 897 specimens from 5 1 samples in the NEFC collec- 

 tion (Table 5). 



Our samples are primarily from inshore waters; however, 

 there are two offshore samples on the continental shelf, one 

 on Georges Bank and one off Chesapeake Bay; the range of 

 the inshore samples is from slightly off the coast of Maine 

 south along the Cape Cod region into Long Island Sound, and 

 to Pamlico Sound and Cape Hatteras, N.C. (Fig. 63; Theroux 

 and Wigley footnote 4, table 110). 



The dwarf surf clam inhabits the Boreal, Virginian, and 

 Carolinian zoogeographic provinces (Coomans 1962); Gosner 

 (1971) placed it only in the Boreal and Virginian provinces. 



This species is a shallow water inhabitant with a depth 

 range extending from + 1 to 28 m (Abbott 1974; Porter 1974). 



Our samples range from to 55 m with a mean of 13 m. The 

 majority of our samples are in the 0-24 m depth range grouping 

 which contains 84% of the samples and 98% of the specimens; 

 the 25-49 m grouping contains 14% of the samples, and 2% of 



the specimens, while the 50-99 m grouping contains 2% of the 

 samples, and < 0.1%' of the specimens (Table 202). 



Abbott (1974) reported that the dwarf surf clam is normally 

 found in sand sediments. 



Among our samples 30% were found in sand which con- 

 tained 24% of the specimens; however, the majority of the 

 specimens (52%) came from silt substrates which contained 

 11% of the samples; silty sand contained 30% of the samples 

 and 8% of the specimens; clay contained 24% of the samples 

 and 16% of the specimens; sand-gravel and sand-shell con- 

 tained significantly smaller amounts of each (Table 203). 

 There are 14 samples containing 143 specimens which are 

 unclassified with regard to sediment type. 



Mulinia sp. Figure 63. 



The NEFC collection contains two specimens from one 

 sample of this genus (Table 5). 



The sample is from the continental shelf south and east of 

 Nantucket Shoals (Fig. 63; Theroux and Wigley footnote 4, 

 table 111), from a water depth of 84 m, in sand. 



Genus Rangia DesMoulins 1832 



Rangia cuneata (Sowerby 1832). Common rangia. Figure 96. 



The common rangia is normally found from northern Ches- 

 apeake Bay to Texas and Mexico (Johnson 1934; Abbott 1968, 

 1974; Morris 1973; Emerson et al. 1976). 



Rangia cuneata is a locally very abundant to common 

 bivalve which inhabits coastal areas and freshwater to brack- 

 ish marshes. Our collection contains nine specimens of this 

 species from four samples (Table 5). 



Our samples are from Pamlico Sound, N.C. (Fig. 96; Ther- 

 oux and Wigley footnote 4, table 170). 



This bivalve is a shallow water inhabitant occupying water 

 depths between 1 and 4 m according to Porter (1974). 



Our samples are from water depths which range between 4 

 and 6 m with a mean of 5 m. This depth range places it in the 

 0-24 m depth range grouping. 



The NEFC samples containing this species were obtained 

 in clay sediments. 



Genus Spisula Gray 1837 



Spisula polynyma (Stimpson, W. 1860). Stimpson's surf clam. 

 Figure 100. 



Stimpson's surf clam is found in both the North Atlantic 

 and North Pacific Oceans. In the Atlantic it ranges from 

 Arctic seas to Rhode Island and in the Pacific from Arctic seas 

 to Puget Sound and is also found at Japan (Johnson 1934: La 

 Rocque 1953; Ockelmann 1958; Morris 1973; Abbott 1974. 

 Emerson et al. 1976). Chamberlin and Stearns (1963) have 

 extended the southern reaches of the range of Stimpson's surf 

 clam to Hudson Canyon. 



The NEFC Specimen Reference Collection contains 14 

 specimens from 2 samples of this species (Table 5). 



Our two samples are from off the tip of Cape Cod, Mass., at 

 Provincetown (Fig. 100; Theroux and Wigley footnote 4, table 

 179). 



37 



