NO. 3574 COPEPOD CRUSTACEANS — LEWIS 69 



Female free fourth pedigerous segment, excluding ala, slightly 

 more than one-third the width of cephalothorax, indistinctly separable 

 from genital segment. Ala broad, extending laterally past lateral 

 edge of genital segment, with 2 large, subrectangular posterior pro- 

 jections overlapping most of genital segment proper. Apex of sinus 

 between lobes of ala flatly concave, posterior edge of lobes sharply 

 angled laterally, with small, lobate projections medially. 



Female genital segment (fig. 25c) convex anteriorly, at junction 

 with fourth pedigerous segment, lateral surface smoothly irregular, 

 with row of spinules along posterior two-thirds of segment. Posterior 

 end of segment drawn out into pair of elongate lobes extending pos- 

 teriorly to end of abdomen, lobes with several rows of spinules and mi- 

 nute spicules (latter not figured). Median lateral surface of lobes 

 also bearing laminate fifth leg projecting laterally and posteriorly. 

 Distal surface of fifth leg (fig. 25e) bearing row of spinules and 2 

 plumose setules. 



Female abdomen 2-segmented, incompletely separated from gen- 

 ital segment dorsally and ventrally. First segment slightly more 

 than half the length of second, with distinct dorsal swelling; second 

 segment elongate, tapered slightly toward distal end, with pak of 

 minute spinules on each side in anterior half of segment. Fine frilled 

 membrane present on ventral-lateral posterior surface, at junction 

 with caudal rami. Caudal rami elongate, rodlike, with small lateral 

 indentation in proximal half, indentation bearing 2 plumose setules; 

 distal end with 3 or 4 setules, longer 2 plumose. 



Male cephalothorax (fig. 256) generally similar to that of female 

 although more elongate. Apex of posterior sinus Avithout lappet- 

 like membrane although remaining membranes present; cross groove 

 of major dorsal grooves with indistinct apex. Ala of free fourth 

 pedigerous segment Avith angular posterior edge but without lobes 

 present in female. Male genital segment (fig. 25d) more orbicular 

 than that of female, without lappet-like projection but with spikelike 

 fifth leg extending to middle of second abdominal segment, inner 

 dorsal surface of leg projecting medially as narrow, heavily sclero- 

 tized flap. Distal end of fifth leg (fig. 25/) with 3 spinules, proximal 

 inner surface with minute, pkmiose setule. Sixth leg (fig. 25g) evi- 

 dent as pair of spinules and single minute, plumose setule adjacent 

 to junction of abdomen and genital segment. Abdomen 2-segmented, 

 distinct from genital segment dorsally, indistinctly separable ven- 

 trally. Second segment approximately 2}^ times the length of first, 

 first without swelling present in female. Caudal rami similar to 

 those of female. 



Female and male antennule (fig. 26a) 2-segmented, attached to 

 lateral-anterior ventral surface of cephalothorax and adjacent sur- 



