NO. 3574 COPEPOD CRUSTACEANS — LEWIS 147 



consisting of 2 nodules, anieriormost with single plumose setule, 

 posterior with 2 plumose setules. Abdomen 1-segmented, broadest 

 anteriorly, constricted at anterior end, tapered to biconcave posterior 

 end. Caudal rami (fig. 54A) subrectangular, with slight concavity 

 on medial inner surface, inner surface plumose. Distal end of rami 

 with 3 long, plumose setae medially, additional seta on outer distal 

 surface, plumose setule on inner surface and second on ventral surface 

 just proximal and medial to outermost seta. 



Male cephalothorax (fig. 54a) similar to that of female, free fourth 

 pedigerous segment slightly shorter, distinct from both cephalothorax 

 and genital segment, with flat or slightly concave dorsal posterior 

 margin instead of convex margin of female. Genital segment (fig. 

 54e) of general barrel shape, lateral surface indented posteriorly, 

 at origin of fifth legs. Fifth legs (fig. 54^) consisting of nodule 

 bearing 3 plumose setules; sixth legs (fig. 54^) situated on posterior- 

 lateral ventral surface, consisting of 2 closely associated plumose 

 setules. Abdomen 1-segmented although incomplete V-shaped band 

 of heavy sclerotization in anterior portion giving 2-segmented ap- 

 pearance. Posterior region of abdomen widest, posterior surface 

 biconcave, with distinct anal depression. Caudal rami (fig. 541) 

 larger than those of female, inner surface convex, plumose in distal 

 half, remaining armature as in female. 



Female and male antennule (fig. 556) 2-segmented, attached to 

 knoblike extension of ventral-lateral anterior surface of cephalothorax, 

 not appearing to be attached to frontal region. First segment 

 slightly more than twice the length of second (male second segment 

 slightly longer), anterior margin bent almost at right angle medially, 

 anterior and anterior ventral surface of distal half of segment bearing 

 approximately 21 lightly plumose setae and setules. Second segment 

 club shaped, distal end with approximately 12 naked setules. Female 

 antenna (fig. 55c) 3-segmented, situated medial and posterior to 

 antennule base. First segment short, squat, irregular, with spike- 

 like projection from posterior distal surface. Second segment strongly 

 developed, broad proximally, tapered to narrower distal end. Third 

 segment fused with clawlike terminal process, bearing setule- 

 like accessory process from proximal inner surface, second from 

 anterior surface. Male antenna (fig. 55d) 3-segmented, first segment 

 irregular, second irregularly club shaped, with indistinct adhesion 

 surface on medial inner surface, with distinct swelhng just distal 

 to adhesion surface, swelling bearing well-defined adhesion surface. 

 Third segment abrupt, terminal process fan shaped, with setule- 

 like accessory process on distal inner surface. 



Female and male mandible (fig. 55c) 4-parted, distalmost part 

 curved inward, bearing 12 denticulations along inner sm-face. Female 



