COPEPODA FROM IFALUK ATOLL 267 



versal rows of spinules. Appendicular seta, setae 1, 4, and 5 fine 

 and short. Setae 2 and 3 lengthened and thickened, especially 

 2nd, which reaches % body length ; seta 3 much shorter. Lengthened 

 setae not swollen at base. 



Antennules (fig. 108a) slender, longer than cephalic somite, 8-seg- 

 mented. Segments 1 and 2 slightly swollen, 4th segment 3 times as 

 long as wide, with small conical process bearing aesthetasc and 2 

 setae. Setation represented in figure 108a. 



Antenna (fig. 1086) with basis and endopodal segment separate; 

 exopodite unsegmented, with 3 marginal setae. Endopodite with 

 7 setae, 4 of which are geniculate. Spine at external margin of 

 endopodite. 



Mandible with elongated praecoxa and small cutting edge; number 

 of teeth could not be counted. Basipodite fairly big, with single 

 strong seta. No exopodite; endopodite unsegmented and small, 

 carries 4 marginal setae (fig. 108c). 



No suitable preparation of the maxillule was obtained. 



Maxilla (fig. 108d) with small praecoxal and small coxal endite, 

 each carrying 2 setae. Basal endite stronger, coalescent with strong 

 curved spine. In addition, there is a fine seta on the basal endite. 



Maxillipede (fig. 108e) chelate, with small coxa and moderately 

 swollen basis. No setae or spinules on coxa and basis. Endopodite 

 represented by single, claw-shaped digit, tapering into fine point, 

 longer than basis. 



Coxa of leg 1 (fig. 108/) with haired external tubercle. Basis with 

 internal and external strong tubercle, in addition to some spinules. 

 Endopodite and exopodite 3-segmented. 3 exopodal segments of 

 about equal length; 2nd with internal seta, 3rd with total of 5 append- 

 ages, 2 of which are geniculate setae. 1st endopodal segment 

 styliform, longer than whole exopodite, iji times as long as broad, 

 with seta at % of internal margin, 2nd and 3rd endopodal segments 

 of about equal length, both with fine internal seta. In addition, 

 there are 2 geniculate setae at apex of segment 3. 



The details of legs 2 to 4 follow from figures 108^^ and from the 

 setal formula: 



endopodite exopodite 



leg 2 1.1.121 0.1.223 



leg 3 1.1.221 0.1.223 



leg 4 1.1.221 0.1.323 



Legs 2 to 4 with 3-segmented exopodites and endopodites. 2nd 

 exopodal segment with haired, 1st with spinulose, external margin. 

 Leg 4 more strongly developed than leg 2 or 3, especially exopodite. 

 Median internal seta of 3rd exopodal segment of leg 4 strongly devel- 



