HAUSTORIIDAE OF NEW ENGLAND BOUSFIELD 165 



of the cold-water Bay of Fimdy (Bousfield, 1962a). On smooth, 

 gently sloping, surf-exposed sand beaches, Amphiporeia virginiana 

 continues northward along the outer coast of Nova Scotia almost to 

 Cape Breton Island. In corresponding estuaries, Pontoporeiafemorata 

 frequents the sandy mud channel banks, and Gammarus lawrencianus, 

 the sandy eel-grass shallows. North of the Scotian shelf, Pontoporeia 

 jemorata and Priscillina armata dominate suitable bottom sediments, 

 and the subarctic estuaries are populated by Pontoporeia affinis, along 

 with Pseiidolibrotus littoralis, Oediceros spp., and other burrowing 

 amphipods. 



Southward from New England, the surf-swept beaches are occu- 

 pied by Protohaustorius longimerus, by a long-rostrate species of 

 Haustoriiis, otherwise very similar to H. canadensis and H. arenarius 

 (Bousfield, in press), and by Neohaustorius schmitzi. Although 

 several of these species persist southward to North Carolina and 

 Georgia, an additional complex of haustoriids, particularly in the 

 Pseudohaustorius and "Lepidactylus" groups, dominate the intertidal 

 and estuarine faunas of the southeastern and Florida-Atlantic coasts. 



As previously noted, the relationship between geographical dis- 

 tribution and phylogeny within the Haustoriidae is simulated closely 

 in other families of amphipods. If of broader application, this 

 relationship may prove useful in the interpretation of the origin and 

 probable lines of diversification within the entire gammaridean 

 suborder of the Amphipoda. 



Family Haustoriidae 



(emendation of Stebbing, 1906) 



Gammaridean amphipods with body and appendages adapted for 

 bm*rowing and mouthparts more or less modified for filtering minute 

 food particles from the interstitial water of bottom sedunents. Head 

 and body segments usually broad and deep, plates and appendages 

 of peraeon and pleon tending to form a ventral cylindrical tunnel 

 through which a strong posteriorly directed water current is main- 

 tained by the action of the powerful pleopods. Rostrum variously 

 developed, not hoodlike. Eyes small, weakly pigmented or lacking. 

 Antennae short, subequal, usually richly plumose or setose; antenna 1 

 with short accessory flagellum and calceolate primary flagellum. 

 Mouthparts tending to enlargement of primary plates and develop- 

 ment of accessory lobes; mandible with large palp and strong molar, 

 incisor and lacinia usually weak; upper lip squarish or broad-rounded; 

 lower lip: inner lobes distinct, elongate. Coxal plates large, deep, 

 margins setose. Gnathopods usually unlike, weakly subchelate, 

 chelate, or simple. Peraeopods 1 and 2 subequal and usually alike, 



