Family DONACIDAE 

 Genus Donax Linne 1758 



Donax sp. Figure 42. 



There are two specimens from one sample of the genus 

 Donax in the NEFC specimen collection (Table 5). 



The one sample in our collection is from nearshore waters 

 along the outer banks between Cape Hatteras and Cape Fear, 

 N.C. (Fig. 42: Theroux and Wigley footnote 4, table 70). 



Our sample is from 18 m of water placing it in the 0-24 m 

 depth range grouping. 



The substrate at the sampling site containing the two speci- 

 mens of wedge shells was sand. 



This species is represented in our collection by two speci- 

 mens from two samples (Table 5). 



Our two samples are from off Portland. Maine, and in 

 Buzzards Bay, Mass. (Fig. 33; Theroux and Wigley footnote 

 4, table 53). 



This species is found in the Boreal, Virginian, and Caroli- 

 nian zoogeographic provinces (Coomans 1962). 



The depth range of this species is from 0.3 to 70 m (Porter 

 1974). 



Our samples are from water depths of 1 and 45 m with a 

 mean of 23 m. The 0-24 m and 25-49 m depth range groupings 

 each contain 50% of both samples and specimens. 



Only one of our samples contained information relating to 

 the type of bottom upon which the organism was found, sand. 



Family SEMELIDAE 

 Genus Abra Lamarck 1818 



Abra sp. Figure 3. 



Although there are several Atlantic species of this genus 

 none have as yet been identified in the NEFC Specimen 

 Reference Collection due to smallness of size or damage to 

 shells. Members of Abra sp. occur in 60 samples yielding 125 

 specimens (Table 5). 



The distribution of our samples of this genus ranges from 

 the entrance of Delaware Bay to off Key West. Fla. (Fig. 3; 

 Theroux and Wigley footnote 4. table 3). 



The main distribution for this genus according to Coomans 

 (1962) is Virginian. Carolinian, and Caribbean in the north- 

 west Atlantic and Celtic in Europe. 



The depth range of our samples is 6 to 500 m with a mean 

 depth of 81 m. The majority of samples are from continental 

 shelf depths of < 200 m. One-third of the samples are in the 

 0-24 m depth range grouping, 25% are in the 100-199 m group- 

 ing and nearly 22% in depths between 25 and 49 m. In terms of 

 density, Abra distribution is greatest (33%) in the shallowest 

 depth range grouping, while 25 and 22% of the specimens are 

 in the 100-199 m and 25-49 m groupings, respectively (Table 

 234). 



Samples containing Abra were most plentiful (35 to 25%) in 

 sandy substrates (sand, sand-shell, and silty sand); somewhat 

 lower quantities (2 to 7%) occurred in other substrates 

 (gravel, shell, and silt). The greatest density of specimens, 

 35%, was found in sand; sand-shell and silty sand substrates 

 each yielded 25% of the specimens; gravel, shell, and silt 

 sediments contained small percentages of specimens (Table 

 235). 



Genus Cumingia Sowerby 1833 



Cumingia tellinoides (Conrad 1830). 8 Tellin-like cumingia. Fi- 

 gure 33. 



The tellin-like cumingia is reported from Canadian waters, 

 and to range from Nova Scotia to Saint Augustine, Fla.; it is 

 also found in Texas (Johnson 1934; La Rocque 1953: Ockel- 

 mann 1958; Abbott 1968, 1974; Morris, 1973; Emerson et al. 



1976). 



"Abbott (1974) has "(Conrad, 1831)" for this species, it should be (Conrad 

 1830). see under References. 



Genus Semele Schumacher 1817 



Semele bellastriata (Conrad 1837). Cancellate semele. Figure 

 97. 



The cancellate semele occurs from Cape Hatteras, N.C, to 

 Florida; it is found at Texas and the West Indies, and at the 

 Bahamas and Bermuda and ranges south to Bahia, Brazil 

 (Johnson 1934; Abbott 1968, 1974; Boss 1972; Morris 1973; 

 Emerson et al. 1976). 



Semele bellastriata is fairly common and is represented in 

 the NEFC collection by 38 specimens from 19 samples (Table 

 5). 



Our samples are on the continental shelf ranging from Cape 

 Fear, N.C, to the midsection of the Florida Peninsula (Fig. 

 97; Theroux and Wigley footnote 4, table 172). 



The published depth range for this species is 2 to 116 m 

 (Porter 1974). 



The range of depth occupied by our samples is 15 to 41 m 

 with a mean of 29 m. The 25-49 m depth range grouping 

 contains 68% of the samples and 79% of the specimens while 

 the 0-24 m grouping contains 35% of the samples and 21% of 

 the specimens (Table 236). 



Boss (1972) reported that the cancellate semele is normally 

 found in coarse sandy substrates. 



Our samples were obtained from sand-shell and sand sub- 

 strates; 63% of the samples and 79% of the specimens oc- 

 curred in the latter and 37% of the samples and 21% of the 

 specimens in the former (Table 237). 



Semele nuculoides (Conrad 1841a). Nuculalike semele. Figure 

 98. 



This species is distributed from North Carolina at Cape 

 Hatteras south through the Gulf of Mexico, it also occurs at 

 the West Indies, the Lesser Antilles, and in the Caribbean, 

 south to Brazil (Johnson 1934; Boss 1972; Morris 1973; 

 Abbott 1974). 



Semele nuculoides is represented in the NEFC Specimen 

 Reference Collection by 146 specimens from 62 samples 

 (Table 5). 



The samples in the NEFC collection range from Cape Hat- 

 teras, N.C, on the continental shelf, south to the middle 

 portion of the Florida Peninsula (Fig. 98; Theroux and Wigley 

 footnote 4, table 173). 



According to Boss (1972) the depth range for this species is 

 between 4 and 183 m. 



43 



