COPEPODS OF THE WOODS HOLE KEGION 465 



plate on the ventral surface, wider and shorter than the dorsal one, 

 with a posterior median sinus, indicating that it is made up of two 

 plates fused. 



Genital segment wider than long, with the genital openings at the 

 posterior corners directed diagonally outward and backward; to 

 each opening is attached a spherical spermatophore, reddish purple 

 in color and nearly half the size of the genital segment. The open- 

 ings of the oviducts are on the dorsal surface, about midway between 

 each lateral margin and the midline; the egg strings are rather 

 slender and more than twice the length of the body. Abdomen 3- 

 segmented, the anal segment as long as the two basal segments 

 combined; caudal rami laminate, almost twice as long as wide, each 

 with three small apical setae. 



The first antennae are apparently 12-segmented, but the segmenta- 

 tion oi the basal half is very indistinct and seems to vary in different 

 specimens. The terminal claw of the second antenna has a curved 

 spine on its inner margin near the center; the base of the claw projects 

 inwardly, and distal to the projection is a hairlike seta; the other 

 segments are unarmed. The terminal claw of the maxillipeds is stout 

 and bent rather abruptly near its tip; on its inner margin are two 

 small spines. 



In the first legs the exopod is relatively shorter and broader than 

 in the two species already described, and is attached closer to the 

 endopod. Its distal segment has two apical setae equal in length. 

 The two segments in each ramus of the second, third, and fourth legs 

 are about the same length, but the basal segment is wider and armed 

 at each distal corner with a short spine, which extends outw^ard along 

 the end segment, but scarcely reaches beyond its center. The end 

 segments of the rami are armed with spines in the following numbers : 

 Second exopod, 7; endopod, 6; third exopod, 5; endopod, 4; fourth 

 exopod, 6 ; endopod, 4. The fifth legs are broad and spatulate, and 

 each is armed with a single apical spine. Total length, 4.5-5 mm. 

 Second segment, 1.75 mm. wide. Egg strings, 10 mm. long. 



Male. — Carapace elliptical, longer than wide, the frontal margin 

 straight; second segment a little wider than, third segment the same 

 width as, the carapace ; fourth segment narrower ; fifth segment two- 

 thirds as wide and one-fourth as long as the fourth segment. Genital 

 segment as wide as the fourth segment and considerably longer; the 

 plate covering this segment reaches entirely around the segment at 

 the anterior end ; on the dorsal surface it does not reach the posterior 

 end of the segment, but leaves the last quarter uncovered; on the 

 ventral surface it only covers the anterior third, and behind it is a 

 pair of ventral plates, one on either side of the mid line, Avhich are 

 divergent and reach farther back than the dorsal plate. The pos- 



