HAUSTORIIDAE OF NEW ENGLAND — BOUSFIELD 191 



^ Pleopod outer ramus 15-20 segmented, slightly the longer. Uropods 

 biramous. Uropod 1 : rami stout, distally broadening, inner longest. 

 Uropod 2 strong, riclily setose, peduncle with stiff spine row. Terminal 

 segment of outer ramus of uropod 3 short or lacking. Telson very 

 broad, shallowly notched, entire, posterior marginal setae long and 

 slender setose. 



Type species. — Pseudohaustorius caroliniensis, new species. 



Additional species. — Pseudohaustorius americanus (Pearse) 1908; 

 Pseudohaustorius borealis, new species. 



Remarks.— The present genus is similar to Eohaustorius Barnard 

 1957 in general aspect of the antennae, mouthparts, and peraeopods; 

 however, the two genera differ significantly in the form of the maxil- 

 liped, lower lip, peraeopod 2, uropod 1, and telson. Similar functional 

 demands may result in convergent evolution of certain appendages 

 in widely separate phylogenetic lines. 



Pseudohaustorius caroliniensis, new species 



Figures 30, 31 



Material examined.— North Falmouth, Mass., intertidal, Aug. 

 17, 1951, M. Pettibone: 1 9, holotype, 1 9, paratype, ov. (USNM 

 collections). 



Description.— Female, 6.5-8.0 m.m.: Head width more than twice 

 the length, broadest posteriorly; rostrum short and broad, acute; 

 antennal sinus shallow; eyes lacking. 



Antenna 1: peduncular segment 3 slender, elongate, terminally 

 bearing 5-6 segmented flagellum; accessory flagellum of two slender 

 subequal segments, markedly subterminal. Antenna 3: peduncular 

 segment 4 deeply expanded posteriorly and distally; segment 5 short, 

 deep; flagellum of 8 unequal segments, subterminal segment longest, 

 proximal segments plumose behind. 



Upper lip minutely pilose at apex. Lower lip : inner lobes relatively 

 narrow. Mandible: incisor conical, simple, left lacinia single, right 

 unequally bifid, 3 accessory blades and one supramolar blade; palp 

 with short terminal segment bearing 14 marginal comb spines and 13 

 slender apical pectinate spines. Maxilla 1: inner plate very small, 

 with 2 marginal setae, outer plate with 11 small spine teeth; palp 

 moderately strong, with marginal plumose setae; accessory baler lobe 

 lacking. Maxilla 2: outer plate small, oblique, distal margin 4- 

 plumose. Maxilliped: inner plate relatively broad and strong; 

 outer plate with weakly toothed inner margin; palp segment 2 with 

 short apical lobe; segment 3 broad clavate and strongly arched. 



Gnathopod 1 : coxal plate shallow, angle subacute, with 7 plumose 

 setae; segment 5 slightly expanded; segment 6 elongate; dactyl 



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