254 BULLETIN 15 8, UNITED STATES NATIONAL MUSEUM 



merit, of fourth leg with one seta on second segment and two on end 

 segment. Fifth legs a triangular lamella, the outer angle represent- 

 ing the outer process of the basal segment and tipped with a filiform 

 seta ; the distal angle passes into a stout and acute spine, with three 

 inner and one outer bristles at its base. Total length, 0.5-0.7 mm. 



Male. — Smaller and more slender than the female, fifth segment 

 a little longer than the fourth; genital segment distinctly divided; 

 caudal rami stouter than in the female, three times as long as wide, 

 Avith a similar armature. First antennae twice geniculate, the seg- 

 ments divided 3, 2, and 2; second antennae with but three apical 

 setae, all geniculate; maxillipeds like those of the female but 

 smaller. Swimming legs showing no sexual modifications ; fifth legs 

 with but a single inner bristle at the base of the apical spine, other- 

 wise as in the female. Total length, 0.45-0.55 mm. 



Remarks. — This copepod may be recognized by its slender elon- 

 gate form in connection with the caudal rami and the fifth legs, 

 the latter projecting beyond the lateral margins of the body in 

 dorsal view. This is the first record of the species outside of 

 Scotland and Norway. 



Genus EVANSULA T. Scott, 1906 



Body elongate and cylindrical, much resembling Leptastacus; head 

 fused with the first segment ; rostrum prominent and well defined at 

 its base ; urosome 4-segmented in female, 5-segmented in male ; genital 

 segment not divided in female, divided in male; caudal rami not 

 longer than anal segment, the apical setae enlarged at the base and 

 geniculate. First antennae 7-segmented, strongly hinged in the male; 

 basal endopod segment of second antenna divided, the 1-segmented 

 exopod attached at the joint ; maxillipeds normally developed. 

 Exopods of swimming legs 3-segmented ; first endopod 2-segmented, 

 second, third, and fourth endopods 1-segmented in female; in the 

 male the second endopod is 1-segmented, the third and fourth endo- 

 pods 2-segmented; the second exopod and the third endopod are 

 sexually modified in the male. The segments of each fifth leg are 

 fused into an elongate lamella, tipped with a large spine with setae on 

 the outer and inner margins. One species found here. 



EVANSULA INCERTA (T. Scott) 

 FlGUBB 166 



Tetragoniceps incerfus T. Scott, 10th Ann. Rep. Fishery Board Scotland' pt. 3, 



p. 254, pi. 12, 1892. 

 Evansia incerla Sars, Crustacea of Norway, vol. 5, p. 415, suppl. pi. 39, 1911. 

 Evansula incerta T. Scott, Proc. Roy. Phys. Soc. Edinburgh, vol. 16, no. 7, p. 342, 



1906. 



Occurrence. — A few specimens of both sexes were washed from the 

 sands on the shore of Katama Bay, Marthas Vineyard, August, 1927. 



