COPEPODS OF THE WOODS HOLE REGION 75 



Male. — Head without a frontal crest and spine; posterior corners 

 of fifth segment shorter than in the female and less angular ; urosome 

 only one-fourth as long as the metasome; fifth legs very asymmetri- 

 cal, right leg 4-segmented, with a short terminal tooth, not reach- 

 ing the end of the first segment of the left leg; the latter 5-seg- 

 mented, the terminal segment hairy and tipped with a seta. Total 

 length, 6.5-7 mm. 



Remarks. — The large strong claw on the second maxillae is the 

 best distinguishing character, together with the large size of the 

 copepod. Rathbun's single sentence gives the first intimation of the 

 color of this species, and it has never before been reported from 

 our American shores. 



Genus BRACHYCALANUS Farran, 1905 



Head separated from the first segment, strongly arched dorsally, 

 with a low crest in the male; fifth segment separated from the 

 fourth, with rounded posterior corners, unarmed in the female, 

 armed with small spines in the male ; urosome 3-segmented in female, 

 5-segmented in male; first antennae much shorter than the meta- 

 some; exopods of first four pairs of legs 3-segmented; first endopod 

 1-segmented; second endopod 2-segmented; third and fourth endo- 

 pods 3-segmented; fifth legs uniramose, 3-segmented in female, 

 biramose, exopods 2-segmented, endopods 1-segmented in male. One 

 species found here. 



BRACHYCALANUS ATLANTICUS (Wolfenden) 

 FlGUKB 51 



XantJiocalanus atlantictis Wolfenden, Jouru. Marine Biol. Assoc, new ser., 

 vol. 7, p. 119, pi. 9, figs. 24, 25, 33, 1904. 



Brachycalanus atlanUcus van Brekmen, Nordisches Plankton, Zoologischer Teil, 

 vol. 4, Entomostraca, Copepoda, p. 66, fig. 77, 1908. 



Occurrence. — A single male from the trawl wings, Station 2230, 

 Albatross, south of Long Island. 



Distribution. — North Atlantic, west of Ireland (Farran, Wolfen- 

 den) ; North Sea (van Breemen). 



Color. — Nothing is known of the color of the living copepod. 



Female. — Head strongly arched, without a crest; genital segment 

 no wider than the abdomen, divided near the center ; caudal rami as 

 wide as long and well separated; basal segment of fifth leg wider 

 than long, its inner margin densely fringed with spines; second 

 segment also wider than long, with smooth margins; end segment 

 twice as long as wide, with two terminal spines, stout and unequal, 



