HAUSTORIIDAE OF NEW ENGLAND — BOUSFIELD 171 



Pleon side plate 3 with posterior spinous process; uropod 1, inner ramus 

 shorter, usually more slender than outer; urosome 2 dorsal margin about 

 equal to that of urosome 3; rostrum and anterolateral angles broad-acute. 



Acanthohaustorius, new genus. 20 



19. Peraeopod 5, posterior margin of segment 4 armed with 3-4 groups of 



spines; uropod 1, concave posterior margin lined throughout with spines, 

 outer ramus with posterior spines only; rostrum extending slightly 

 anterior of lateral angles (European- Atlantic only). 



Haustorius arenarius (Slabber) 



Peraeopod 5, posterior margin of segment 4 with one group of spines only; 



uropod 1, posterior marginal spines concentrated proximally and distally, 



both rami with spines and long setae; rostrum variable in length, may 



reach half length of antennal peduncular segment 1. 



Haustorius canadensis Bousfield (p. 197) 



20. Telson cleft nearly to base, posteromedial margins broadly convex; peraeopod 



4, distal margin of segment 5 subtruncate; uropod 1, inner ramus slender, 



setae singly inserted; mature animals small (4-12 mm.) 21 



Telson sharply U -cleft, }4 to base, lobes subtruncate behind; peraeopod 4, 

 distal margin of segment 5 oblique; uropod 1, inner ramus strong, posterior 

 marginal setae in clusters; animals medium-large (10-14 mm.) 



Acanthohaustorius spinosus (Bousfield) (p. 204) 



21. Pleosome 3, posterodorsal margin produced as a large subconial process, 



side plate with short weak spinous process; peraeopod 5, coxal plate 

 posteriorly quadrate, posterior lobe of segment 4 short, posterior and 

 proximal margins continuous, with 1 spine. 



Acanthohaustorius intermedins, new species (p. 202) 



Pleosome 3, posterodorsal margin normally rounded behind, side plate with 



large spinous process ; peraeopod 5, coxal plate posteriorly acute, hindlobe 



of segment 4 elongate, posterior margin distinct, with 2 spines ... 22 



22. Uropod 1, inner ramus very slender and short, about J4 length of outer 



ramus; peduncle strongly spinose posteriorly; gnathopod 1, segment 5 

 slightly inflated; telson broad, lobes broader than long. 



Acanthohaustorius shoemakeri, new species (p. 204) 

 Uropod 1, inner ramus nearly equal in length to outer ramus, peduncle with 

 few posterior marginal spines; gnathopod 1, segment 5 strongly inflated, 

 powerful; telson lobes as broad as long. 



Acanthohaustorius millsi, new species (p. 199) 



Subfamily Pontoporeiinae 



Genus Bathyporeia Lindstrom 



Bathyporeia qiioddyensis Shoemaker 1949 



Material examined. — Woods Hole, Mass., near Nobska Pt., 

 sandy beach below low water, Aug. 16, 1959, E. L. Mills.: 1 9, ov., 

 5.0 mm., 1 imm. (NMC 7080); east side Nobska Pt., fine sand at 

 low water, July 28, 1962, E. L. Mills.: 1 cf, 5.0 mm.; 1 9 ov., 4.0 

 mm. (NMC 7081). 



Cape Cod region, Mass., Meganset, at breakwater, fine sand, 

 low water, Sept. 2, 1963: 2 cf cf, 5 99; Little Sippewisset Marsh, 

 beach at mouth, low water, Sept. 8, 1963: 1 cf, 21 99; Wild Harbor, 



