Our samples are from continental shelf and upper slope 

 waters south of Nantucket Shoals, south to the offing of 

 Chesapeake Bay (Fig. 81; Theroux and Wigley footnote 4, 

 table 138). 



Gosner (1971) reported the inflated pandora from the 

 Carolinian zoogeographic province. 



The range in depth of this species is from 48 to 165 m (Boss 

 and Merrill 1965; Abbott 1974). 



The range in depth for our samples is 21 to 194 m with a 

 mean of 107 m. The majority of both samples and specimens 

 are in the 100-199 m depth range grouping where 59 and 68%, 

 respectively, occur; the 25-49 m grouping and the 50-99 m 

 grouping each contain 18% of the samples but 18 and 12% of 

 the specimens, respectively; the smallest number of samples 

 and specimens are in the 0-24 m depth range grouping which 

 contains 6% of the samples and 3% of the specimens (Table 

 280). 



The NEFC samples of the inflated pandora were obtained 

 from three sediment types with the majority occurring in silty 

 sand substrates which contained 53% of the samples and 50% 

 of the specimens, while sand substrates contained 41% of the 

 samples and 47% of the specimens; sand-gravel contained 6 

 and 3%, respectively (Table 281). 



Pandora inornata Verrill and Bush 1898. Inornate pandora. 

 Figure 82. 



The inornate pandora occurs from Newfoundland to Cape 

 Cod, Mass. (Johnson 1934; Ockelmann 1958; Boss and Mer- 

 rill 1965; Abbott 1974). 



Pandora inornata is an uncommon species, of which there 

 are 159 specimens from 21 samples in the NEFC collection 

 (Table 5). 



Our samples are from the continental shelf on Georges 

 Bank and in the Cape Code region (Fig. 82; Theroux and 

 Wigley footnote 4, table 139). 



Both Johnson (1934) and Abbott (1974) reported that this 

 species occupies water depths between 18 and 82 m. 



The NEFC samples are from water depths which range 

 between 1 and 79 m with a mean of 34 m. The majority of 

 samples are in the 0-24 m depth range grouping which con- 

 tains 57% of the samples; however, this grouping only con- 

 tains 33% of the specimens; the 25-49 m grouping contains 

 29% of the samples and 20% of the specimens, while the 50-99 

 m grouping, although containing 14% of the samples, contains 

 the majority of the specimens, 47% (Table 282). 



The distribution of samples and specimens in bottom sedi- 

 ment types ranging from coarsest to finest grained is as fol- 

 lows: three sediment types, gravel, sand-gravel, and sand- 

 shell each contained 9% of the samples but 6, 1 , and 1% of the 

 specimens, respectively; sand contained the greatest 

 amounts, 55% for samples and 88% of the specimens, while 

 silty sand contained 18% of the samples and 4% of the speci- 

 mens (Table 283). There are 10 samples containing 49 speci- 

 mens which are unclassified with regard to sediment type. 



Pandora trilineata Say 1822. Say's pandora. Figure 82. 



The distribution of this species is from North Carolina to 

 Florida and Texas (Johnson 1934; Boss and Merrill 1965; 

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



Pandora trilineata is a moderately common bivalve of 

 which the NEFC collection contains 11 specimens from 9 

 samples (Table 5). 



Our samples are from the continental shelf from slightly 

 north of Cape Hatteras, N.C., south to the central section of 

 the Florida Peninsula (Fig. 82; Theroux and Wigley footnote 

 4, table 140). 



According to Morris (1973), Abbott (1974), and Porter 

 (1974), the range of depth in which this species may be found 

 is between and 110 m. 



Our samples are from water depths which range between 1 1 

 and 33 m with a mean of 2 1 m. Two-thirds of the samples are in 

 the 0-24 m depth range grouping which contains 73% of the 

 specimens, the remaining 33% of the samples are in the 25-49 

 m grouping, which contains 27% of the specimens (Table 

 284). 



The majority of both samples and specimens occurred in 

 sand substrates which contained 78% of the samples and 82% 

 of the specimens: the only other substrate type in which this 

 species occurred in our sample suite was sand-shell which 

 contained 22% of the samples and 18% of the specimens 

 (Table 285). 



Pandora sp. Figure 83. 



The NEFC collection contains 8 samples from which 11 

 specimens are identified to the generic level of Pandora sp. 

 (Table 5). 



Our samples are from the continental shelf between Cape 

 Cod, Mass., and Cape Fear, N.C., with one sample occurring 

 in the eastern portion of the Gulf of Maine adjacent to Georges 

 Bank (Fig. 83; Theroux and Wigley footnote 4, table 141). 



Our samples range in depth between 15 and 230 m with a 

 mean of 72 m. The majority of both samples and specimens 

 are in the 50-99 m depth range grouping which contains 38% of 

 the samples and 36% of the specimens; 25% of the samples 

 and 27% of the specimens are in the 0-24 m depth range 

 grouping, the same percentage of samples (25%), but 18% of 

 the specimens occurs in the 25-49 m grouping while the 200- 

 499 m depth range grouping contains 13% of the samples and 

 18% of the specimens (Table 286). 



Samples yielding specimens of the genus Pandora occurred 

 in two substrate types, sand and silty sand. Eighty-three 

 percent of the samples and 75% of the specimens occurred in 

 sand; and 17% of the samples and 25% of the specimens 

 occurred in silty sand (Table 287). There are two samples 

 containing three specimens which are unclassified with re- 

 gard to sediment type. 



Family LYONSIIDAE 

 Genus Lyonsia Turton 1822 



Lyonsia arenosa Moller 1842. Sanded lyonsia. Figure 56. 



This small bivalve enjoys a wide distribution both in the 

 Atlantic and Pacific Oceans. In the Atlantic it ranges from 

 Greenland to Cape Ann , Mass . , and in the Pacific from Alaska 

 to Vancouver, British Columbia, and to Japan (Johnson 1934; 

 La Rocque 1953; Clarke 1962; Morris 1973; Abbott 1974). 



This is a moderately common bivalve species of which 

 there are 81 specimens from 20 samples in the NEFC collec- 

 tion (Table 5). 



52 



