COPEPODA FROM IFALUK ATOLL 257 



Ameira minuta Boeck, 1864 



Figures 103, 104 



Ameira minuta Boeck, 1864, p. 273. — Fraser, 1936, p. 26. — Nicholls, 1939, p. 

 271.— Lang, 1948, p. 789, figs. 316 (no. 2), 317 (no. 2).— Klie, 1950, p. 88.— 

 Roe, 1958, p. 230. 



Material.— Log. 431, 1 ov. 9, 0.35 mm. Loc. 589, 3 ov. 99, 0.33, 

 0.35, 0.36 mm. Loc. 638, 1 ad. 9, 0.30 mm. 



Description. — The following is based on the female specimen of 

 0.35 mm. length from locality 589. 



Adult female, total length 0.35 mm.; greatest diameter 0.11 mm.; 

 length of longest fm^cal seta 0.25 mm. 



General shape of body slender, without sharp demarcation between 

 cephalothorax and abdomen, which have nearly same length (propor- 

 tion 12:11). Cephalothorax with very slightly curved, almost 

 parallel walls, anterior part rounded, deeply incised at insertion of 

 antennules; rostrum distinctly visible in dorsal ^^ew as small, tri- 

 angular projection between antennular bases, as long as 1st antennular 

 segment (fig. 1036). Head and 1st thoracic somite fused, cephalic 

 somite slightly longer than combined lengths of thoracic somites 2 to 

 4; back smoothly curving into rostrum, sides produced to cover basal 

 parts of oral appendages (fig. 103a). Rostrum with fairly thick base, 

 pointing obliquely forward. Epimeral plates of thoracic somites 2 

 and 3 cut off squarely; extreme lateral apex of 4th somite rounded. 



Thoracic somite 5 small, visible as narrow band in dorsal and lateral 

 aspects. Genital somite composed of fused abdominal somites 1 and 

 2, line of fusion distinctly visible dorsally and ventrally, as long as 

 combined lengths of abdominal somites 3 and 4, which have same 

 length. Completely closed row of spinules along distal end of genital 

 and 3rd abdominal somites. Some spinules on lateral surface of somite 

 1 near line of fusion. Anal somite longer than preceding somite, with 

 broad, nude anal plate. Insertion of widely separated furcal rami 

 bordered with spinules ; some additional spinules on sides. 



Furcal rami slightly broader than long (proportion 5:4), with 5 

 marginal setae and 1 appendicular seta. Appendicular seta and setae 

 1, 4, and 5 fine but fairly long; setae 2 and 3 lengthened and thickened, 

 especially the 2nd. Both setae shghtly swollen at base. Distal end of 

 caudal rami cut off obliquely. 



Antennules slightly shorter than cephalic somite, 8-segmented; 2nd 

 segment long, 4th with conical process bearing aesthetasc and 2 setae; 

 process covers nearly whole of segment 5. Setation represented in 

 figure 104/. 



Basis and 1st endopodal segment of antenna separate. Exopodite 

 small, 1 -segmented, with 3 long setae and 1 spine. Endopodite with 8 

 appendages, 4 of which are geniculate setae (fig. 104y). 



