COPEPODA FROM IFALUK ATOLL 347 



Esola longicauda Edwards, 1891 



Figures 132a, 137a,6, 138, 139, 141c 



Esola longicauda Edwards, 1891, p. 81, pi. 3 (figs. 16-26). — Lang, 1944, p. 37; 



1948, p. 1409, figs. 571 (no. 1), 572.— Noodt, 1955, p. 91, figs. 96-100.— 



Petkovski, 1955, p. 126. 

 Laophonte hulhifera Norman, 1911, p. 137, pi. 28 (figs. 1-7). — Sewell, 1940, pp. 



312, 325, 352, 359, 366, 371.— NichoUs, 1941, p. 423; 1941b, pp. 98-101; 



1945, p. 10. 

 Laophonte rhodiaca Brian, 1928, pp. 29-37, figs. 122-129.— Nicholls, 1941, p. 



423; 1941b, p. 105, 107; 1945, p. 10, fig. 6a. 



Material. — Loc. 590, 1 ov. 9, 0.32 mm.; 1 ad. cf , 0.29 mm. Loc. 

 592, 1 9 cop. stage V, 0.39 mm.; 1 ad. 9, 0.51 mm.; 5 ad. cf cf, 

 0.27-0.41 mm. (0.36 mm.). 



Description. — The following is based on a female of 0.51 mm. and 

 a male of 0.41 mm., both from locality 592; they have been dissected 

 and mounted. 



Adult female, total length 0.51 mm.; greatest diameter 0.12 mm.; 

 length of longest f ureal seta 0.41 mm. 



General shape of body slender, gi-eatest diameter at end of cephalic 

 somite, anteriorly rounded, posteriorly very gradually narrowing, 

 slightly broader in genital region. Head and 1st thoracic somite 

 fused; cephalic somite as long as combined lengths of thoracic somites 

 2 to 4 (fig. 1376). Back in lateral aspect almost straight, anterior 

 part curving into rostrum, which forms solid protuberance on head, 

 directed obliquely forward and downward, reaching middle of 1st 

 antennular segment (fig. 137a). Sides of cephalic somite consider- 

 ably produced to shield oral appendages. Rostrum, in dorsal aspect, 

 with fairly broad base, apex cut off squarely, with two fine hairs of 

 frontal organ. Two cup-shaped depressions in integument of ce- 

 phalic somite, one on each side of middorsal line behind insertion of 

 antennules, probably representing eyes. 2nd to 4th thoracic somites 

 of equal length; epimeral plates of these somites rounded and bor- 

 dered with spinules. 



5th thoracic somite distinctly visible dorsally and laterally, fairly 

 short. 1st and 2nd abdomnial somites, forming genital somite, of 

 equal length, with distinct line of fusion and with epimeral plates 

 with distinct laterocaudally produced flap. 3rd and 4th abdominal 

 somites of same length, each slightly longer than preceding somite, 

 3rd also with laterocaudally produced epimeral plates. Anal somite, 

 half as long as w4de, with broadly rounded anal flap bordered with 

 fine hau's. All somites of body, including cephalic and anal somites, 

 have their distal border fringed with small spinules. 



Furcal rami (fig. 138^) characteristically shaped, slightly longer 

 than anal somite. External furcal wall almost straight; internal 

 border strongly swollen proxhnally; swellmg bordered on dorsal 



