The NEFC samples are from water depths ranging between 

 1 and 15 m with a mean of 5 m, which places them in the 0-24 

 depth range grouping (Table 256). 



Only three of our samples, containing eight specimens, had 

 sediment information included in the sampling data. Two 

 samples (67%) occurred in silty sand substrates, containing 

 six specimens (75%); one sample occurred in sand-gravel and 

 contained two specimens (Table 257). The remaining 6 sam- 

 ples with 13 specimens are unclassified with regard to sedi- 

 ment type. 



Genus Periglypta Jukes-Browne 1914 



Periglypta listen (Gray 1838). Princess venus. Figure 85. 



The princess venus occurs from southeast Florida to the 

 West Indies and to southern Texas (Johnson 1934: Morris 

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



Periglypta listen is a moderately common warm water 

 bivalve of which there are six specimens from two samples in 

 the NEFC collection (Table 5). 



Our two samples are from the continental shelf, one off the 

 Florida keys, the other off the central coast of Florida (Fig. 

 85; Theroux and Wigley footnote 4, table 146). 



Both Morris (1973) and Abbott (1974) reported that this is a 

 shallow water inhabitant while Emerson et al. (1976) reported 

 that it is occasionally found on beaches. 



The two samples in the NEFC collection are from water 

 depths of 7 1 and 84 m. This depth range places both samples in 

 the 50-99 m depth range grouping. 



Two sediment types were involved in the distribution of 

 this species, sand-shell and silty sand, each of which con- 

 tained 50% of the samples; 17% of the specimens occurred in 

 sand-shell, while 83% of the specimens occurred in silty sand. 



Genus Pitar Roemer 1857 



Pilar morrhuanus Linsley 1845. 9 Morrhua venus. Figure 89. 



Pitar morrhuanus is a fairly common species, especially off 

 the New England coast; there are 723 specimens from 102 

 samples in the NEFC Specimen Reference Collection (Table 

 5). 



The morrhua venus is distributed from the Gulf of St. 

 Lawrence and Prince Edward Island to approximately North 

 Carolina (Johnson 1934; Morris 1951, 1973; LaRocque 1953; 

 Ockelmann 1958; Abbott 1968, 1974; Emerson et al. 1976). 



The samples in our collection are distributed on the con- 

 tinental shelf from Maine to Cape Hatteras, N.C. (Fig. 89; 

 Theroux and Wigley footnote 4, table 153). 



This species is an inhabitant of the Boreal and Virginian 

 provinces of the northwest Atlantic (Coomans 1962; Gosner 

 1971). 



The published depth range for this species is 4 to 183 m 

 (Abbott 1968; Gosner 1971). 



Our samples are from depths which range between and 

 900 m with a mean of 62 m. The anomalous deep water record 

 involves only one small juvenile clam, the majority were well 



'Abbott 0974) has 'Linsley. 1848" for this species, it should be Linsley 1845, 

 see under References. 



within normal depths for this species. The majority of both 

 samples and specimens are in the shallowest depth range 

 grouping, 0-24 m, which contains 35% of the samples and 80% 

 of the specimens; the 25-49 m depth range grouping contains 

 24% of the samples and 7% of the specimens; the 50-99 m 

 grouping, 32% of the samples and 10% of the specimens: the 

 remaining three groupings, 100-199, 200-499, and 500-999 m 

 contain 5% or less of the samples and 1.4 to 0.1% of the 

 specimens (Table 258). 



Two sediment types predominated for this species, sand 

 and silty sand; these substrates contained 62 and 25% of the 

 samples, respectively, and 63 and 25% of the specimens, 

 respectively: other sediment types in which the species 

 occurred, in significantly smaller amounts, were till, sand- 

 shell, silt, and clay. Table 259 lists the abundances for these 

 sediment types of samples and specimens. There are 13 sam- 

 ples containing 468 specimens which are unclassified with 

 regard to sediment type. 



Pitar sp. Figure 90. 



Samples containing members of this genus are distributed 

 from south of Cape Hatteras on the continental shelf to the 

 Florida Keys (Fig. 90; Theroux and Wigley footnote 4. table 

 154). 



The NEFC Specimen Reference Collection contains 130 

 specimens from 60 samples of bivalves which are classified to 

 the generic level Pitar (Table 5). 



The NEFC samples are from depths which range between 

 13 and 102 m with a mean of 33 m. The majority of these 

 samples are in the 25-49 m depth range grouping which con- 

 tains 70% of the samples and 72% of the specimens ; the 0-24 m 

 grouping contains 25% of the samples and 23% of the speci- 

 mens, while the two range groupings in deeper areas, the 

 50-99 m and 100-199 m contain 3.3 and 2%, respectively, for 

 samples and 4 and 1%, respectively, for specimens (Table 

 260). 



Sand and sand-shell substrates were the preferred sediment 

 types for this genus, with sand the leader accounting for 68% 

 of the samples and 69% of the specimens; sand-shell con- 

 tained 22% of the samples and 23% of the specimens: other 

 sediment types in which samples containing Pitar were found 

 were gravel, with 2% of the samples and 2% of the specimens, 

 shell, with 3% of the samples and 2% of the specimens, and 

 silty sand where 5% of the former and 5% of the latter were 

 obtained (Table 261). 



Family PETRICOLIDAE 

 Genus Petricola Lamarck 1801 



Petricola pholadiformis Lamarck 1818. False angel wing. Figure 

 88. 



The false angel wing is a widely distributed species occur- 

 ring in both the Atlantic and Pacific Oceans. In the northwest 

 Atlantic it ranges from the Gulf of St. Lawrence into the Gulf 

 of Mexico to Texas ; it is also present in the Caribbean south to 

 Uruguay; it also occurs in the Mediterranean Sea. Black Sea. 

 and along the west African coast to Senegal, and the French 

 Congo; in the Pacific it occurs at California (Johnson 1934: 

 Morris 1951, 1973; LaRocque 1953; Ockelmann 1958:Tebble 

 1966; Abbott 1968, 1974; Emerson et al. 1976). 



47 



