PARASITIC COPEPOD CRUSTACEANS — LEWIS 127 



spikelike processes dorsally, 1 ventrally, processes adjacent to ovid- 

 ucal opening. Fifth thoracic leg (presumably) a plumose setule in 

 posterior third of genital segment, arising from swollen lateral ventral 

 surface. Sixth leg (presumably) a nodule bearing 3 plumose setules, 

 situated lateral and just anterior to oviducal opening. Ventral sur- 

 face of genital segment with numerous minute, clawlike processes on 

 lateral ventral sm-f ace in anterior half in addition to numerous minute, 

 hairlike processes over most of ventral surface. 



Abdomen (fig. 31a) elongate, 2-segmented, first segment slightly 

 shorter than second, second segment swollen posteriorly and, in some 

 specimens, with indistinct, incomplete line at anterior end of swelling 

 that suggests a 3-segmented condition as described by Wilson (1907a). 

 Abdomen distinct from genital segment dorsally, fused ventrally; 

 posterior end of second segment angled to anal indentation. Caudal 

 rami longer than wide, lateral margins almost parallel except at 

 anterior and posterior ends; inner margin plumose, posterior margin 

 irregular, posterior surface bearing 2 long, plumose setae medially, 2 

 short setae from outer lateral surface and 1 minute setule from inner 

 siu-face. Both abdomen and caudal rami with numerous minute, 

 hairlike projections. 



Antennule (figs. 31d, e) 2-segmented, attached to lateral-antero- 

 ventral cephalothoracic surface. Second segment slightly less than 

 three-fourths the length of first, first broader proximally than distally, 

 with ridge along most of ventral surface bearing approximately 19 

 plumose setae. Second segment elongate, slightly narrower prox- 

 imally than distally, bearing single naked setule from middle of 

 posterior sm-face, 10 naked setules from distal surface. Antenna 

 (fig. 31e) 3-segmented, attached posterior and medial to antennule 

 base. First and second segments short, hregular, combined lengths 

 approximately one-third the length of thhd segment and terminal 

 process; first segment with small, conical process bearing minute 

 plumosites. Third segment and terminal process fused, forming long, 

 claw-shaped structure, with 2 setule-like accessory processes, prox- 

 imalmost appearing finely plumose. Mandible (fig. 31e) rod-shaped, 

 slightly swollen proximal end articulating in platelike region of heavy 

 sclerotization. Distal end of mandible flattened, curved medially, 

 inner margin with 12 denticulations. Postantermal process (fig. 31e) 

 long and clawlike, situated lateral to antenna base and posterior and 

 lateral to antennule base, without process-bearing nodules present on 

 euryphorids and caligids. Postoral process (fig. 31e) 2-parted, ap- 

 pearing to originate from platelike area of hairy sclerotization forming 

 articulation surface for mandible. Posterior part of process elongate, 

 bifurcate distally, outer tine longer than inner; anterior part a nodule 

 bearing single, naked setule. Maxilla 2-segmented, situated posterior 



