COPEPODA FROM IFALUK ATOLL 261 



Ameira parvula (Claus, 1866) 



Figures 105a,6, IO60-/ 



CanthocanipUis pamihis Claus, 1866, p. 30, pi. 5 (figs. 1-6). 



Ameira parvula.— Yktova, 1928, p. 183.— Nicholls, 1939, pp. 271, 272.— Sewell, 

 1940, pp. 300, 301, 352, 359, 366, 369, 371, 372, 373, 375.— Nicholls, 1941b, 

 p. 85.— de Vos, 1945, p. 77, figs. 79, 80.— Lang, 1948, p. 790, figs. 316 (no. 3), 

 317 (no. 3).— Klie, 1950, p. 88, fig. 8.— Caspers, 1951, p. 65.— Ax, 1952, p. 

 239.— Gallingani, 1952, p. 75.— Noodt, 1952, p. 109.— Bo2ic, 1955, p. 8, pi. 4 

 (figs. 1-6).— Noodt, 1955, p. 78; 1955a, p. 207.— Schutz and Kinne, 1956, p. 

 113.— Maghraby and Perkins, 1956, p. 492.— BScesco, et al., 1957, p. 345, 

 fig. 13h.— Noodt, 1957, p. 153.— Stock and de Vos, 1960, p. 206.— Marcus 

 and P6r, 1961, pp. 124, 125. 



Material.— Loc. 591, 4 ad. 99, 0.39-0.43 mm. (0.41 mm.). 



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

 0.39 mm. length, which has been dissected and mounted. 



Adult female, total length 0.39 mm.; greatest diameter 0.10 mm.; 

 length of longest furcal seta 0.37 mm. 



General shape of body greatly resembling condition observed in 

 Ameira minuta; cephalo thorax, however, narrows very gradually an- 

 teriorly and, consequently, is more or less spindle-shaped (fig. 1056). 

 Greatest diameter of body at end of cephalic somite; cephalothorax 

 and abdomen indistinctly separate. Head and 1st thoracic somite 

 completely fused to form cephalic somite, which is as long as combined 

 lengths of thoracic somites 2 to 4; sides moderately produced to 

 shield basal parts of oral appendages; extreme lateral apex rounded 

 (fig. 105a). Back almost straight, rostrum small, frontal part of head 

 only slightly incised at insertion of antennules. Rostrum a triangular 

 protrusion, half length of 1st antennular segment, pointing obliquely 

 downward. Epimeral plates of thoracic somites 2 to 4 cut off squarely. 

 There are several internal chitinous ridges on the cephalothorax, 

 serving, apparently, as places of attachment for muscles. There is a 

 pair of short, transversal ridges at the level of the oral aperture left and 

 right of the middorsal line on the cephalic somite, and some chitinized 

 tubercles along the distal edge of the cephalic somite. Transversal 

 ridges also occur on the 3rd and 4th thoracic somites, left and right 

 of the middorsal line. 



5th thoracic somite distinctly visible, short. Genital somite com- 

 posed of fused 1st and 2nd abdominal somites, slightly longer than 

 combined lengths of somites 3 and 4, which have about same length. 

 There is a distinct line of fusion on the genital somite. Spinules 

 occur on the laterodorsal and lateroventral sides of the 1st (near line 

 of fusion), the 2nd, and the 3rd somites; the 4th is nude. Anal somite 

 as long as 4th, with laterally some spinules. Anal flap broadly 

 rounded, nude. Insertion of furcal rami without spinules. 



