COPEPODS OF THE WOODS HOLE REGION 



309 



Female. — Cephalic segment about half the length of the body; 

 urosome less than half the length of the metasome, its segments 

 fringed on their posterior margins with small spinules ; rostrum large, 

 triangular, squarely truncated, and tipped with two movable juxta- 

 posed spines. First antennae 6-segmented, the two basal segments 

 well separated, the aesthetask on the third segment more than three 

 times the length of the last three segments combined, and twice 

 jointed at its base, both joints bearing setae. Basal segment of 

 second antenna shorter than the second segment, the end segment with 

 six stout marginal spines. Terminal segment of first exopod with 

 two filiform setae and two coarse spines, all apical; fifth legs fused 

 across the midline into a single lamina, with a shallow median apical 



FiGUBB 186. — Metis jousseaumei: a. Mandibular palp ; b, female, 

 lateral ; c, maxillipeds ; d, rostrum ; e, female, fifth leg ; f, 

 female, first leg ; g, caudal rami ; h, female, second antenna ; 

 t, female, first antenna. (Prom R. W. Sharpe, Proc. U. S. 

 Nat. Mus., vol. 38, p. 423) 



sinus. Each half has two laminate apical lobes, the inner one longer 

 than the outer and sharply pointed. On the outer margin of each 

 half is a filiform seta, representing the outer process of the basal 

 segment. Total length, 0.35-0.5 mm. 



Male. — Smaller and less swollen than the female; first antennae 

 8-segmented, prehensile, the two basal segments distinctly sepa- 

 rated, the third and fourth segments each with a slender aesthetask, 

 the seventh segment converted into a blunt claw. On each side of 

 the ventral surface of the rostrum, beneath the base of the apical 

 movable spine, is a slender seta with an enlarged bulbous base, and 

 between the two bulbs on the midline is a small triangular process. 

 The apical spines of the rostrum are smooth, shining, and blunt at 

 their tips, which are in contact with each other. The terminal seg- 



