Figure 6.— Geographic distribution of species from the families Argissidae, Bateidae. and Calliopiidae in the Mid- 

 dle Atlantic Bight. 



lections is probably the result of its preference for rocky 

 bottoms, which we were unable to sample with our gear. 



Family CALLIOPIIDAE 



Calliopius laeviusculus (Kr^yer) 1838 



This widely distributed species is found throughout 

 the arctic and subarctic regions of the Atlantic and Pa- 

 cific Oceans, and occurs from Labrador south to New 

 Jersey along the east coast of North America (Bousfield 

 1973). Calliopius laeviusculus occurred in low densities 

 (2-19/m^) at two stations south of Cape Cod in 18 and 33 

 m on sand bottoms (Fig. 6). According to Steele and 

 Steele (1973), C. laeviusculus is usually found clinging 

 to algae on rocky shores, but it also swarms in the plank- 

 ton during the summer. Its habitat preference for rocky 

 shores explains its scarcity in our collections. 



Family COROPHIIDAE 



Corophium acutum Chevreux 1908 



This species is nearly cosmopolitan in warm tem- 

 perate regions and is found from Florida north to Cape 



Cod along the eastern coast of North America (Bous- 

 field 1973). In our collections, C. acutum occurred at two 

 stations in the upper Chesapeake Bay in shallow water 

 (7-16 m) on mud bottoms (Fig. 7). 



Corophium crassicome Bruzelius 1859 



Geographic Distribution. This species is distributed 

 throughout the arctic-boreal regions of the North Atlan- 

 tic and Northeast Pacific, and has previously been taken 

 as far south as Long Island Sound along the east coast of 

 North America (Lie 1968; Bousfield 1973). We collected 

 C crassicorne in 96 samples from 84 stations between 

 Cape Cod and the mouth of Chesapeake Bay (Fig. 7). 

 The 47 records south of Long Island extend the range of 

 this species to Virginia. This species was rather abun- 

 dant with a mean density of 110/m^, ranging between 

 2/m^ and 3,200/m^. Corophium crassicorne shows a clear 

 pattern of decreasing abundance from north to south 

 with the mean density going from 2(X)/m^ in southern 

 New England to 40/m2 in the New York Bight to 9/m2 in 

 the Chesapeake Bight. 



Bathymetric Distribution. Bousfield (1973) reported 

 that this species may be found subtidally to 2(X) m. In 

 our samples, C. crassicorne occurred between 15 and 77 

 m with the largest concentration of samples (54/95), oc- 



12 



