COPEPODA FROM IFALUK ATOLL 51 



2-segmented, with strongly haired seta at base of basal segment 

 (presumably coxa) and 3-terminal, claw-shaped setae at end of apical 

 segment. 



Legs 1 to 3 with 3-segmented endopodites and exopodites; leg 4 

 with transversally elongated coxa and basis, and 3-segmented exop- 

 odite and 1-segmented endopodite. The various particulars of the 

 legs appear from the setal formula, figures 14:a-d, and the following 

 notes. Setal formula: 



Leg 4 (fig. 14:d) with styliform endopodite, 1-segmented, with 2 

 unequal spiniform setae. 3rd exopodal segment with 2 spines along 

 the external margin. 



Leg 5 (fig. 13c) styliform, 1-segmented, gradually tapering towards 

 the apex and there with 2 setae, one of which is thickened, about % the 

 length of the 5th leg. 



Color a light horny yellow. No eye visible. 



Adult male, total length 0.90 mm.; greatest diameter 0.33 mm. 



The adult male resembles the adult female in many respects; a 

 complete description, therefore, is unnecessary. Cephalothorax, in 

 two males present, trifle slenderer and less broadly rounded, with indi- 

 cation of being squarish. Rostrum as in female. 



Abdomen 6-segmented; genital somite large and swollen, slightly 

 longer than broad (proportion 13:11), swollen laterally and with 

 indication of ventral swelling. Shape can best be judged from figures 

 12d,e; genital apertures closed, ventrally, by 2 huge plates, each 

 drawn out laterally into short, strong point, preceded by two fine 

 setae at external border. Abdominal somites 2 and 3 of same length; 

 4 and 5 also of same length, each slightly shorter than 2nd or 3rd. 

 Anal somite and furca as in female. 



Antennules as in female, one of setae on 2nd, 3rd, and 4th segments 

 modified to form aesthetasc, bringing total number of aesthetascs on 

 male antennule to 4. 



Antenna and mouth parts as in female, with exception of maxilli- 

 peds. These, in the male, are chelate and powerfully developed. 

 Coxa short, asetose; basis big and swollen, with an internal, longi- 

 tudinal row of strong, blunt teeth. Endopodite long and slender, 

 longer than basis and slightly curved, forming well-developed, slender 

 digit, with fine seta at its base and spoon-shaped, dilated part at 

 apex (fig. 13d). 



