COPEPODA FROM IFALUK ATOLL 323 



Laophonte ifalukensis, new species 



Figures 127, 128c, 129, 130 



Material. — Loc. 589, 1 ad. 9, 0.42 mm. Loc. 591, 5 ad. 9, 0.39- 

 0.45 mm. (0.43 mm.). Loc. 592, 1 ov. 9, 0.48 mm.; 1 ad. d', 0.3G mm. 

 Loc. 638, 3 ov. 99, 0.42-0.45 mm. (0.44 mm.); 2 ad. cTc^, 0.43 and 

 0.45 mm. 



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

 locality 589 (holotype). Since this holotype fragmented during 

 handling, some drawings of the undissected female have been made 

 from the ovigeroiis female paratype specimen from locality 592, The 

 male allotype is from locality 592; all other specimens have been 

 labelled as paratypes. 



Adult female, total length 0.42 mm.; length of longest furcal seta 

 0.26 mm. 



General shape of bodj" elongate in dorsal aspect, with greatest 

 diameter at end of cephalic somite, distmctly dilated at genital somite. 

 Head and 1st thoracic somite fused to form cephalic somite, which is 

 as long as combmed lengths of thoracic somites 2 to 5. Back, in 

 lateral aspect, almost straight and running into short, slightly curved 

 rostrum (fig. 127a). Sides of cephalic somite moderately produced to 

 cover basal parts of oral appendages; lateroventral border con- 

 siderably produced backwardly. Rostrum broad triangular plate, 

 rounded at apex, which has two minor incisions, each with hair of 

 frontal organ. Rostrum directed forward and slightly downward, 

 not separated from head. Thoracic somites 2 to 4 of nearly equal 

 length, with distinctly visible, rounded epimeral plates bordered with 

 spinules. 5th thoracic somite slightly longer than preceding somite. 



Genital somite composed of fused abdominal somites 1 and 2, line 

 of fusion visible dorsaUy and invisible ventrally. 3rd abdominal 

 somite slightly longer than 2nd, as 2nd with laterally expanded wings, 

 exact shape of which can best be judged from figure 128c. Wing 

 (epimeral plates) visible both dorsaUy and ventrally. 4th abdominal 

 and anal somite of equal length ; 4th normally developed. All thoracic 

 and abdominal somites, including cephalic somite, distally bordered 

 with fine spinules along dorsal and dorsolateral walls. Anal somite 

 has broad anal plate, also bordered with spinules, insertion of furcal 

 rami also fringed with spinules. 



Furcal rami twice as long as broad, very slightly diverging, external 

 border almost straight, internal border slightly convex and spinulose. 

 Each ramus with 5 marginal setae and 1 appendicular seta (fig. 1276). 

 Setae, 1, 4, 5, and appendicular seta fine and short; setae 2 and 3 

 lengthened and thickened, especially the 2nd; both not swollen at 

 base. Setae 4 and 5 placed close together at distal part of external 

 border. 



