158 PROCEEDINGS OF THE NATIONAL MUSEUM vor. los 



Posterior edges of the segments with a complete dorsal fringe, that 

 of segments 1-2 indistinctly serrate, that of segment 3 deeply serrate. 



External genital field defined by sclerotization, the distal edge of 

 operculum a flaplike opening, the right side rounded (fig. 31). 



Caudal setae exactly like those of gracilis, except that the two 

 long middle setae are not jointed at their bases. 



Appendages differing very little from those of gracilis. Antennule 

 longer, reaching to the end of the genital segment; clearly 26-seg- 

 mented, the proportions of the segments and numerical setation 

 exactly like gracilis except that the last four segments tend to greater 

 elongation, and segment 24 is nearly subequal to 25 and 26; the long 

 setae of segments 4, 8, 10, 13, and 22 comparatively shorter; the 

 surface spinules of segments 13-22 arranged in single rows extending 

 across the entire distal edge of the segment, size of spinules varying 

 from segment to segment. Segmentation and setation of antenna 

 and mandible palp like gracilis. Maxillule like gracilis except that 

 the first of the two laciniae just distad to the gnathobase has five 

 instead of four setae. Maxilla also with six large lobes, of which 

 two belong to the basal portion; the apical portion clearly 2-segmented, 

 a difference from gracilis that might be an individual variation or due 

 to position in mounting. Maxilliped exactly like that of gracilis. 



Legs 1-4 identical to gracilis in an-angement, structure, and number 

 of setae and spines. Leg 1 differing slightly in that the spinous 

 process between the outer spine and flattened process of exopod 

 segment 2 is as long as the distal process instead of shorter; the inner 

 apical spine of segment 3 about as long as segments 2+3. 



Leg 5 (fig. 28) very similar to that of gracilis. Basal portions of 

 all jointed setae of exopod and endopod comparatively shorter; that 

 of exopod 2 hardly reaching beyond segment, first two setae of exopod 

 3 reaching about to point of insertion of succeeding setae. Endopod 

 segment 2, first outer seta set below middle of segment, at point about 

 64 percent of total length; first inner seta set a little above the middle, 

 at a point about 42 percent of total length; spinous process of outer 

 margin short, only about 10 percent of total length of segment. (See 

 also p. 170.) 



Figures 28-37. — Ridgewayia shoemakeri, new species, and Ridgezvayia sp. (Tortugas). 

 28-35: R. shoemakeri, new species: 28, female, leg 5; 29, male, right antennule, apical 

 segments; 30, male, right antennule, segments 9-16, with armature of segments 10, 13, 

 14; 31, female, genital operculum; 32, male, habitus, lateral; 33, male, leg 5, detail apex 

 of left exopod, anterior view; 34, same, posteromedial view; 35, male, leg 5, anterior 

 view, with detail apex of right exopod. 36, 37, Ridgewayia sp. (Tortugas), male 

 copepodid stage V: 36, leg 5, posterior view; 37, left antennule, segments 8-13, with 

 armature of segment 9. 



