PARASITIC COPEPOD CRUSTACEANS — LEWIS 97 



Distribution. — Mediterranean, England, warmer parts of the At- 

 lantic (Steenstrup and Liitken, 1861), Tongatabu (Friendly Islands). 



Material.— One adult male (USNM 110810) collected by E. C. 

 Jones and Kenneth Sherman from the fin of a specimen of Prionace 

 glauca captured by longline at 40°15'N., 170°16'W. Although the 

 specimen was collected out of the Hawaiian area, the presence of the 

 host around the Hawaiian Islands and the known distribution of the 

 parasite suggest its probable occurrence in the area. 



Measurements. — One adult male: 



{mm.) 



Greatest length, excluding setae 15.54 



Greatest length of cephalothorax 7.42 



Greatest width of cephalothorax, excluding membranes 7.42 



Greatest length of genital segment 3.85 



Greatest width of genital segment 3.36 



Greatest length of abdomen 1.68 



Greatest length of caudal rami 2.73 



Diagnostic description of male. — Cephalothorax (fig. 17a) 

 approximately as wide as long, consisting of cephalic maxilliped- 

 bearing and first pedigerous segments. Frontal region narrow, 

 separated from remaining cephalothorax by distinct line of division. 

 Membrane-rimmed lateral cephalothoracic margins smoothly convex, 

 posterolateral regions extending well posterior of posterior median 

 cephalothoracic region and forming, with lateral margins of free 

 second pedigerous segment, distinct sinuses. Membrane on lateral 

 cephalothoracic margins continuous around posterior extension of 

 lateral regions, terminating at anterior end of sinus; additional mem- 

 brane present, projecting dorsally and extending transversely across 

 anterior end of sinus. Dorsal cephalothoracic grooves distinct, ex- 

 tending anteriorly from sinus apex, curving laterally sharply just 

 anterior to ocular region, terminating at lateral margin just posterior 

 to antennule. Eyes small, with small pigmented region around each 

 lens, pigmented regions of both eyes contiguous on median longi- 

 tudinal axis of body. 



Second, third, and fourth pedigerous segments (fig. 176) free, 

 second and third indistinctly and incompletely fused. Second seg- 

 ment narrower anteriorly than posteriorly, width much greater than 

 length, lateral margins concave anteriorly, convex posteriorly, la- 

 teroposterior regions extending laterally as winglike processes with 

 membranous margins. Third pedigerous segment slightly narrower 

 than second, broader anteriorly than posteriorly, without winglike 

 projections but with pair of small, knoblike projections at junction 

 with second pedigerous segment. Fourth pedigerous segment distinct 



