(Bousfield 1973). We collected E. brasiliensis at four sta- 

 tions: two from Vineyard Sound and two from Chesa- 

 peake Bay (Fig. 18). These records occurred between 10 

 and 37 m on sand, gravel, and shelly bottoms. Its den- 

 sity at the four stations ranged from Vm'^ to 125/m'^. The 

 scarcity of records of E. brasiliensis in our collections is 

 undoubtedly due to the small number of our samples 

 taken in estuaries. 



stations where /. anguipes occurred ranged between 18 

 and 63 m. We found this species on both sand (6/12) and 

 gravel (6/12) bottoms, but the mean densities on gravel 

 (100/m^) were much higher than on sand (lO/m'''). Since 

 /. anguipes occurs most frequently on hard substrata 

 (i.e., rocks, pilings, and aids to navigation), it is 

 probably much more common than our grab sampling 

 indicates. 



Ericthoniua rubricomis Smith 1873 



Jaaaa falcata (Montagu) 1818 



Geographic Distribution. This amphi-Atlantic species 

 has previously been recorded in the western Atlantic, 

 between the Gulf of St. Lawrence and Long Island 

 Sound (Bousfield 1973). In our collections from the Mid- 

 dle Atlantic Bight, E. rubricornis occurred in 59 samples 

 from 53 stations between Cape Cod and Cape Hatteras 

 (Fig. 18). The 39 records south of Long Island extend the 

 range of this species to Cape Hatteras. Ericthonius 

 rubricornis has a mean density of 30/m^ ranging 

 between 2/m2 and 720/m2. 



Bathy metric Distribution. Bousfield (1973) reported 

 that this species may be found from low water to over 

 200 m. In our collections, E. rubricornis occurred 

 between 40 and 376 m with the bulk of the records 

 (44/59) occurring between 50 and 89 m (Table 35). The 

 density of this species was quite low (2-12/m2) at the sta- 

 tions below 100 m. 



Table 35. — Bathymetric distribution of Ericthoniua 

 rubricomig in samples from Middle Atlantic Bight. 



This tube-dwelling amphipod is a dominant fouling 

 organism which is cosmopolitan in temperate and warm 

 temperate seas (Barnard 1969). Along the North 

 American Atlantic coast, J. falcata occurs northward to 

 Newfoundland (Bousfield 1973). We collected this 

 species at a single station in the lower Chesapeake (Fig. 

 18), but it is known to be a common species on hard sub- 

 strata throughout our study area. 



Table 36.— Sediment associations of Erichthoniu* ru- 

 bricornis in samples from Middle Atlantic Bight. 



Family LILJEBORGIIDAE 



Idunella sp. A 



This species did not correspond to the description of 

 any known member of the genus Idunella. Idunella sp. A 

 occurred at nine stations between Cape Cod and Cape 

 Hatteras along the outer edge of the continental shelf 

 (Fig. 19). Its density was uniformly low (2-10/m^). The 

 collections of this undescribed species occurred between 

 121 and 225 m on sand (6/11), silty-sand (4/11), and 

 shell (1/11) sediments. 



Sediment Relationship. This tube-dwelling amphi- 

 pod lives primarily on sand bottoms (Bousfield 1973). 

 We collected E. rubricornis on sediments ranging from 

 gravel to sand-silt-clay, but the bulk (48/59) of the sam- 

 ples and the highest densities (40/m^) occurred on stind 

 bottoms (Table 36). 



lachyroceruB anguipes Krrfyer 1838 



According to Bousfield (1973), this tube-dwelling 

 species occurs along the American Atlantic coast south 

 to Cape Hatteras on hard substrata to depths >50 m. In 

 our Middle Atlantic Bight collections, this species oc- 

 curred at 11 stations between Cape Cod and Maryland 

 (Fig. 18) in low to moderate densities (4-370/m2). The 



LHjeborgia sp. A 



These specimens could not be positively identified as 

 any known species of Liljeboria. They did bear a close 

 resemblance to L. kinahani, but they differed in several 

 important morphological features. We collected this 

 species at four stations between Cape May and Cape 

 Hatteras (Fig. 19). Its density was low (3-40/m^) at all 

 stations. This species was distributed between 20 and 40 

 m on sand (3/4) and sand-gravel (1/4) sediments. 



Listriella bamardi Wigley 1966 



According to Bousfield (1973), this species is dis- 

 tributed from the south side of Cape Cod to Georgia. It 



33 



