N.J. We collected P. obliquua at 32 stations between 

 Cape Cod and Norfolk, Vs. (Fig. 10). The 19 stations 

 south of Sandy Hook extend the range of this species. 

 The mean density of this species was high (110/m^), 

 ranging between 2/ni^ and 1,400/m''. Its mean density 

 decreased to the south ranging from 260/m^ in southern 

 New England to 11/m' in the Chesapeake Bight. 



Bathymetric Distribution. According to Bousfield 

 (197,3), P. obliquua occurs from low water to 50 m. We 

 collected this spiecies between 13 and 91 m. but the bulk 

 of the records (28/33) were taken in <50 m (Table 17). 

 Pseudunciola obliquua showed no consistent trend in its 

 density within its depth range. Its bathymetric range 

 did not change with latitude. 



Sediment Relatonship. This tube-dwelling species has 

 been collected on medium to coarse sand (Bousfield 

 1973). In our collections, P. obliquua occurred on sedi- 

 ments ranging from sand-gravel to sand-silt, but it oc- 

 curred most frequently (26/33) and in the highest den- 

 sities (130/m^) on sand bottoms (Table 18). 



Table 17.— Bathy-metric distribution of Pseudunciola 

 obliquua in samples from Middle Atlantic Bight. 



Table 18. — Sediment associations of Pseudunciola ob- 

 liquua in samples from Middle Atlantic Bight. 



side of Cape Cod and New Jersey. We collected S. 

 smithianus at 16 stations between Cape Cod and Mary- 

 land (Fig. 10). This species was in low density at all sta- 

 tions with a mean of 9/m^ ranging between 2/m^ and 

 40/m-. It occurred between 13 and 86 m, but was most 

 common (11/16) between 40 and 60 m. The collections of 

 this species came from shelly sand (2/16), silty sand 

 (1/16), and sand (13/16) bottoms. 



Unciola inermia Shoemaker 1945 



Geographic Distribution. This species has been 

 reported between the Bay of Fundy and the mouth of 

 Chesapeake Bay (Shoemaker 1945b). We collected 106 

 samples at 92 stations between Cajie Cod and Cap)e 

 Charles (Fig. 10). Unciola inermis was abundant with a 

 mean density of 560/m-, ranging between 2/m'^ and 

 6,100/m-'. The mean density of this species was highest 

 in southern New England (1,250/m^) and decreased sub- 

 stantially in the New York (230/m-) and Chesapeake 

 (220/m-)" Bights. 



Bathymetric Distribution. Shoemaker (1945b) found 

 this species between low water and 200 m, but the ma- 

 jority of his records came from about 60 m. We collected 

 U. inermis between 14 and 84 m, but the highest den- 

 sities (720-1, 000/m-) and the majority of the samples 

 (71/106) occurred between 30 and 59 m (Table 19). This 

 species was found at greater depths (>70 m) in the 

 southern portion of its range, showing a clear pattern of 

 submergence. 



Table 19.— Bathymetric distribution of I'nciola iner 

 mi» in samples from Middle .Atlantic Bight. 



RUdardanus laminoaa (Pearse) 1912 



This species has previously been collected in the 

 Caribbean and the Gulf of Mexico at 40-60 m 

 (Shoemaker 1945b). Our collections from two stations 

 off Virginia and North Carolina (Fig. 10) extended the 

 range of this species to the north. These records came 

 from 77 and 80 m on shelly sand and shell bottoms. The 

 density for R. laminosa was low (6/m^) at both stations. 



Siphonoecetea smithianus Rathbun 1908 



According to Bousfield (1973), this species has been 

 recorded from only a few localities between the south 



Sediment Relationship. According to Bousfield (1973), 

 U. inermis occurs on sand and silty sand sediments. We 

 collected this species on sediments ranging from sand- 

 gravel to sand (Table 20). The highest mean density oc- 



Table 20.— Sediment associations of I'nciola inermit 

 in samples from Middle Atlantic Bight. 



18 



