NO. 3574 COPEPOD CRUSTACEANS — LEWIS 87 



Description. — Female cephalo thorax (fig. 31a) oblong, consisting 

 of cephalon and first 4 thoracic segments. Frontal region with dor- 

 sally facing lunule-like modification laterally, with deep incision medi- 

 ally and fine membrane along anterior ventral sm-face median to modi- 

 fication. Lunular modifications (fig. 326) with denticulated, dorsally 

 facing anterior margin, beaiing single setule posteriorly. Division 

 between frontal region and cephalothorax distinct; 2 large, subtri- 

 angular projections present, extending anteriorly to posterior region of 

 lunular modifications from origin on lateral anterior surface of cephalo- 

 thorax. Posterior two-thirds of median cephalothoracic region raised 

 dorsally, above lateral cephalothoracic regions. Lateral surface of 

 cephalothorax forming distinct fiange ventrally, bearing fine membrane 

 along entire length. Posterior sinus (fig. 31c) distinct, slender, with 

 heavily sclerotized lateral surface, bearing fine membrane along outer 

 surface. Posterior end of median cephalothoracic region extending 

 well past posterior end of lateral regions, covering anterior end of free 

 fourth pedigerous segment. Major dorsal cephalothoracic grooves 

 running longitudinally, cross groove absent. Free fourth pedigerous 

 segment slender, without dorsal plates. 



Female genital segment (fig. 31f/) ovoid, indistinctly separable from 

 free fourth pedigerous segment. Posterior end of segment irregular, 

 irregularities primarily in region of oviducal openings. Fifth leg 

 (fig. 31/) consisting of 5 plumose setules on lateral ventral surface 

 just lateral to oviducal opening. 



Female abdomen 1 -segmented, distinct from genital segment. 

 Caudal rami subrectangular, irregular distally, inner surface plumose ; 

 distal region with 4 plumose setae and 2 plumose setules. 



Male cephalothorax (fig. 316) differing from female in shape (circu- 

 lar), in absence of lunular modification of frontal region, in absence of 

 deep median incision of frontal region, in membrane projecting from 

 anterior edge of frontal region instead of from anterior ventral surface. 

 Also differing in concave nature of posterior median cephalothoracic 

 region, with large, lappet-shaped projection extending over anterior 

 half of free fovirth pedigerous segment and forming attachment surface 

 of segment. Median cephalothoracic region with fine cuticular exten- 

 sion dorsally, extension covering concave posterior margin of region 

 and most of lappet-shaped projection. Free fourth pedigerous 



Figure 32. — Lepeophtheirust fallolunulus, new species, ventral view: a, left caudal ramus; 

 b, female frontal region, right side showing lunule-like structure (dorsal view); c, right 

 antennule; d, female oral region, right side showing antenna, postantennal process, mouth 

 cone, mandible, maxillule (ma-1), postoral process (pop), postoral adhesion process (pa), 

 and maxilla base (ma-2); e, male oral region, right side showing antenna (stippled), 

 postantennal process, mouth cone (hatched), mandible (hatched), maxillule (ma-1), 

 postoral process (pop), postoral adhesion process (pa) and maxilla base (ma-2); /, 

 right maxilla; g, female left maxilliped; h, male right maxilliped. 



