toms. All 31 samples from the Middle Atlantic Bight 

 were taken from sand bottoms. 



Ampelisca uncinata Chevreux 1887 



Mills (1971) reported the occurrence of A. uncinata on 

 the continental slope south of Cape Cod between 460 

 and 1,100 m. He suggested that this species may be 

 widespread in the North Altantic at bathyal depths 

 (350-1,100 m). Ampelisca uncinata occurred in our col- 

 lections at two stations on the continental slope south of 

 Cape Cod and Long Island (Fig. 5). Both of these sta- 

 tions were on sand bottoms at a depth of 450 m. The 

 density of this species was low at both stations (3-7 /m^). 



Ampelisca vadorum Mills 1962 



Geographic Distribution. Mills (1964) reported that 

 this species is distributed from the Gulf of St. Lawrence 

 to the Gulf of Mexico. We collected A. vadorum in 76 

 samples from 74 stations from Cape Cod to Cape Hat- 

 teras (Fig. 5). This species was moderately abundant 

 with a mean density of 70/m'', ranging from 2/m2 to 

 l,900/m2. There was no evidence for a latitudinal trend 

 in the abundance of this species within the area sam- 

 pled, but it is worth noting that A. vadorum occurred 

 much less frequently in the New York Bight area. 



Mills (1963, 1964) indicated that A. vadorum occurred 

 principally in the protected waters of bays and estuaries 

 like its sibling species A. abdita. However, we collected 

 A. vadorum much more frequently in the open waters of 

 the continental shelf than in protected waters. 



Bathymetric Distribution. Ampelisca vadorum has 

 been recorded from low intertidal down to 70 m (Bous- 

 field 1973). In our samples, this species occurred be- 

 tween 8 and 104 m. Although it was relatively common 

 between 10 and 70 m, the highest mean densities (130- 

 190/m2) occurred between 10 and 29 m (Table 6). The 

 bathymetric distribution of A. vadorum did not change 

 along the latitudinal gradient within our study area. 



Table 6. — Bathymetric distribution of Ampelisca va- 

 dorum in samples from Middle Atlantic Bight. 



on sediments ranging from sand-gravel to sand-silt 

 (Table 7). The majority of the samples (54/76) and the 

 highest mean density (90/m^) occurred on sand bottoms. 



Table 7. — Sediment associations of Ampeluca va- 

 dorum in samples from Middle Atlantic Bight. 



Ampelisca verrilli Mills 1%7 



Geographic Distribution. This species has been 

 reported from shallow coastal waters off eastern North 

 America from Cape Cod to Cape Hatteras (Mills 1967b). 

 We collected A. verrilli at 33 stations between Massa- 

 chusetts and North Carolina (Fig. 5). This species oc- 

 curred in both the protected waters of bays and es- 

 tuaries, and along the open coast. This was an abundant 

 species at the stations where it occurred with a mean 

 density of 250/m^, ranging between 2/m'^ and 2,700/m^. 

 There was no evidence for a latitudinal trend in the den- 

 sity of this species. 



Bathymetric Distribution. Bousfield (1973) gave the 

 depth range of A. verrilli as 0-50 m. We collected this 

 species between 4 and 37 m. The highest mean density 

 (410/m^) and 55% of the samples occurred between 10 

 and 19 m (Table 8). This temperate water species did 

 not change its bathymetric distribution within the 

 latitudinal gradient of our study area. 



Table 8. — Bathymetric distribution of Ampelisca ver- 

 rilli in samples from Middle Atlantic Bight. 



Sediment Relationship. According to Bousfield (1973), 

 A. vadorum is most commonly found in medium to 

 coarse sands and shelly sands. We collected A. vadorum 



Sediment Relationship. Mills (1967b) found that A. 

 verrilli occurred most frequently on coarse sands. We 

 collected A. verrilli on sediments ranging from shell to 

 silty sand (Table 9). This species occurred most fre- 

 quently on sand bottoms (22/33), but its mean density 

 was also high (240-370/m^) on shell and sand-shell sedi- 

 ments. 



Byblis gaimardi Kn^yer 1846 



Mills (1971) reported that this circumpolar species oc- 

 curs throughout the North Atlantic and Arctic Oceans 

 from Iceland to Alaska. In the western Atltintic, this 



