COPEPODA FROM IFALUK ATOLL 203 



Genus Amphiascopsis Gurney, 1927 

 Amphiascopsis cinctus (Claus, 1866) 



Figures 76-81 



Dactylopus cinctus Claus, 1866, p. 27, pi. 3 (figs. 8-12). 



Amphiascus cinctus.— -Vhiova, 1928, p. 182.— Nicholls, 1939, p. 261.— Sewell, 



1940, pp. 256, 352, 358, 363, 366, 367, 369, 370, 373, 375, 376, figs. 54, 55; 



1949, p. 172. 

 Amphiascopsis cinctus. — Nicholls, 1941b, pp. 71, 73, 75, 76. — Lang, 1944, p. 



17.— Dahl, 1948, p. 98.— Lang, 1948, p. 666, fig. 269 (no. 1).— Sewell, 1949, 



p. 172.— Klie, 1950, p. SO.— Roe, 1958, p. 229; 1960, p. 283. 

 Amphiascus ceylonicus. — Nicholls, 1939, p. 261; 1941b, pp. 75, 76. 

 Amphiascus havelocki.—WichoWs, 1939, p. 259.— Sewell, 1940, pp. 127, 285, 358, 



363.— Nicholls, 1941b, pp. 75, 77. 

 Amphiascopsis havelocki. — Krishnaswamy, 1953a, p. 71. 

 Amphiascus imperator. — Nicholls, 1939, p. 261; 1941b, pp. 75, 76. 

 Amphiascus lagunaris. — Sewell, 1940, p. 265. 

 Amphiascopsis lagunaris. — Nicholls, 1941b, p. 77. 

 Amphiascopsis australis Nicholls, 1941, p. 414, fig. 17; 1941b, pp. 71, 75, 77. — 



Sewell, 1949, p. 172. 



Material.— Loc. 425, 1 ad. 9, 0.60 mm. Loc. 431, 1 ov. 9, 0.65 

 mm.; 2 ad. cf cf , 0.54 and 0.59 mm. Loc. 589, 2 ov. 99, 0.62 and 0.66 

 mm.; 1 9 cop. V, 0.53 mm.; 2 ad. cf cf , 0.54 and 0.60 mm. Loc. 590, 

 1 9 cop. V, 0.48 mm. Loc. 592, 1 ad. cf, 1.02 mm. Harry Sta. 41, 

 1 ad. 9, 0.67 mm.; 1 ad. cf, 0.68 mm. 



Description. — The 0.66-mm.-long ovigerous female from locality 

 589 and the adult male from locality 592 wiW be described completely. 

 Some additional information on two slightly aberrant specimens is also 

 presented. 



Adult female (loc. 589), 0.66 mm.; greatest diameter 0.18 mm.; 

 longest furcal seta 0.29 mm.; proportional length of cephalothorax 

 and abdomen is 23:21. 



Body long and slender, in dorsal aspect walls of cephalic somite 

 almost parallel, very gradually narrowing anteriorly and posteriorly 

 (fig. 77a). Separation between cephalothorax and abdomen marked 

 by sHght constriction behind 5th thoracic somite. Head and 1st 

 thoracic somite fused to form cephalic somite, slightly longer than 

 combined lengths of thoracic somites 2 to 4. Line of back, in lateral 

 view, smoothly curved into prominent rostrum (fig. 776). Rostrum, 

 in dorsal view, placed in deep depression between insertion of anten- 

 nules, separated from cephalic somite by shallow groove, curved, 

 pointing forward, reaching halfway 2nd antennular segment. Two 

 fine hairs of frontal organ are very distinctly visible. Laterally ce- 

 phaUc somite is well produced, covering basal parts of oral append- 

 ages. Thoracic somites 2 to 4 of equal length, epimeral plates 

 rounded. 



