Table 9.— Sediment associations of \mpelwca ver- 

 rilU in samples from Middle Atlantic Bight. 



Sediment 



type 



Sand-gravel 



Shell 



Sand-shell 



Sand 



Sand-silt 



Silt-clay 



species has been reported from Greenland south to Cape 

 Cod between 5 and 575 m (Mills 1971). We collected a 

 single specimen of B. gaimardi along the northernmost 

 transect of our study area (Fig. 5). This station was at 

 185 m depth on a sand bottom. The absence of further 

 records to the south supports Mills' (1971) description of 

 the geographic range of this species. 



Byblia aerrata Smith 1873 



Geographic Distribution. This species has been 

 reported from the south side of Cape Cod to Chesa- 

 peake Bay (Mills 1971). In our Middle Atlantic Bight 

 collections, B. serrata occurred in 145 samples from 130 

 stations between Cape Cod and Cape Hatteras (Fig. 5). 

 This species was relatively abundant in our samples with 

 a mean density of 290/m^, ranging between 2/m^ and 

 9,200/m2. There was no evidence of a latitudinal trend in 

 the density of this species. 



Bathymetric Distribution. According to Mills (1971), 

 B. serrata occurs from intertidal depths to 2(X) m. We 

 collected B. serrata between 10 and 201 m. The majority 

 of the samples (116/145) occurred between 20 and 69 m 

 with the highest mean density (1,400/m^), occurring be- 

 tween 20 and 29 m (Table 10). It is worth noting that 

 this species is absent from waters shallower than 40 m 

 off southern New Jersey and Mtuyland, but it is com- 

 monly found in water as shallow as 15 m off Virginia and 

 North Carolina. This distribution pattern cannot be ex- 

 plained with presently available environmental data, 

 but other species (i.e., Leptocheirus pinguis) show a 

 similar pattern. 



Table 10. — Bathymetric distribution of Byblia aerrata 

 in samples from Middle Atlantic Bight. 



Sediment Relationship. Byblis serrata occurs most fre- 

 quently on medium to coarse sand bottoms (Bousfield 

 1973). We collected B. serrata on sediment types rang- 

 ing from sand-gravel to sand-silt, but it occurred most 

 frequently (117/145), and in the highest densities 

 (350/m^), on sand bottoms (Table 11). 



Table II. — Sediment associations of ByblU aerrata in 

 aamplea from the Middle Atlantic Bight. 



Haploops aimilis Stephensen 1925 



Mills (1971) found this species south of Capte Cod on 

 the continental slope between 800 and 2,900 m. He sug- 

 gested that this species may be widespread in the North 

 Atlantic at bathyal depths although it has been reported 

 only from a few scattered localities. We collected H. 

 similis at six stations from the continental slojje and rise 

 between lat. 38°N and 40°N (Fig. 5). The stations were 

 located between 491 and 2,840 m on silt (4/6), silty sand 

 (1/6), and clay (1/6) bottoms. The density of this species 

 was uniformly low (2-4/m^). 



Family ARGISSIDAE 



Argiasa hamatipea (Norman) 1869 



This widely distributed species occurs throughout the 

 subarctic regions of both the Atlantic and Pacific 

 Oceans (Barnard 1971; Bousfield 1973). In the western 

 Atlantic, A. hamatipes has been reported from Labrador 

 south to North Carolina between 5 and 100 m on sand 

 and gravel sediments (Bousfield 1973; Fox and Bynum 

 1975). This species occurred at seven of our stations just 

 south of Martha's Vineyard (Fig. 6). These records came 

 from between 38 and 73 m on sand (4/7) and silty sand 

 (3/7) bottoms. The density of this sp>ecie8 was low (10- 

 20/m2) at all seven stations. 



Family BATEIDAE 



Batea catharinenaia Miiller 1865 



Bousfield (1973) reported that this warm temperate 

 species may be found from the south side of Cape Cod to 

 Florida and the Gulf of Mexico. This species is found 

 subtidally to 20 m on stony and gravelly bottoms. We 

 collected B. catharinensis at two stations in Buzzards 

 Bay at 10 and 18 m on sand and silty sand bottoms (Fig. 

 6). The density of the species was low at both stations 

 (10-16/m''). The scarcity of B. catharinensis in our col- 



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