COPEPODA FROM IFALUK ATOLL 197 



2. Furcal rami much wider than long, with marginal setae 2 and 3 

 greatly lengthened and thickened, both also swollen at base, especially 

 seta 2, which has fairly extended swollen part. 



3. Exopodite of antenna 3-segmented, but setae number 1, 0, and 3, 

 respectively. 



4. 3rd exopodal segment of leg 4 with 3 internal setae. 

 Remarks. — Amphiascus minutus is distributed throughout the 



entire Atlantic, from the Arctic seas, along both the American and 

 European coasts, down into Antarctic waters; its distribution has 

 been discussed by Lang (1948, p. 651). The following localities have 

 since been made known: the Oresund strait between Denmark and 

 Sweden (Dahl, 1948); the Helgoland area in Germany (Klie, 1950); 

 the Dalkey area in County Dublin and Lough Ine in County Cork, 

 Ireland (Roe, 1958, 1960); the Plymouth area in England (Eraser, 

 1936; Marine Biological Association, 1931, 1957); the Whitstable 

 area in County Kent, England (Maglu-aby and Perkins, 1956); and 

 the Adriatic (Petkovsld, 1955b). The species occurs in sand samples, 

 in washings of algae, and in the plankton. The present records seem 

 to represent the first Pacific records of this species; in the Ifaluk col- 

 lection it occurred in sand samples taken at various intervals from the 

 reef border and in crevices near the reef margin. 



Amphiascus hirtus Gurney 



Figures 73-75 



Amphiascus hirtus Gurney, 1927, p. 523, fig. 142. — Monard, 1928a, pp. 371, 

 384.— Lang, 1934, p. 32, figs. 71, 72.— NichoUs, 1939, p. 263.— Sewell, 1940, 

 pp. 358, 363.— Nicholls, 1941b, pp. 75, 76.— Lang, 1948, p. 654, fig. 264 

 (no. 2). 



Material. — Loc. 590, 1 ov. 9, 0.44 mm.; 1 ad. cf, 0.29 mm. 



Description. — The following is based on the above-mentioned 

 specimens; both have been dissected and mounted. 



Adult female, total length 0.44 mm.; length of longest furcal seta 

 0.14 mm. 



General shape of body almost as in Amphiascus minutus; moder- 

 ately slender in dorsal aspect, with division between cephalothorax 

 and abdomen indistinctly marked. Greatest diameter of body at 

 end of cephalic somite; anterior portion narrowing and rounded; 

 posteriorly very gradually narrowing. Head and 1st thoracic somite 

 fused, length of cephalic somite slightly exceeds that of thoracic 

 somites 2 to 4 combined. Back, in lateral view, gently curved, 

 continuing in slender rostrum (fig. 73a). Rostrum as in A. minutus, 

 curved, slender, apex rounded, separated from cephalic somite by 

 shallow groove and as long as antennular segments 1 and 2. Thoracic 



