240 U-S. NATIONAL MUSEUM BULLETIN 23 6 



cephalic somite much produced and completely shielding oral ap- 

 pendages. Kostrum short, with broad base, which is only partly 

 visible from above, apex blunt (fig. 95/). Thoracic somites 2 to 4 of 

 equal length; epimeral plates rounded and backwardly slightly pro- 

 duced, accentuated by small distal incision. 



5th thoracic somite very narrow, scarcely visible in dorsal or lateral 

 aspect. Abdomen 5-segmented, but 1st and 2nd somites separate, 

 4th and anal somite indistinctly separated. Somites 1 to 4 of equal 

 length, anal somite slightly longer. Anal operculum small, rounded, 

 and nude. All abdominal somites are nude. 



Furcal rami widely separate, divergent, slightly narrowing distally. 

 Each ramus has 5 marginal setae and 1 appendicular seta. Seta 1, 3, 

 and appendicular seta fine and small; seta 4 slightly stronger. Seta 

 2 considerably lengthened and thickened, reaching half body length. 

 Seta 5 short and spiniform. 



Antennules (fig. 95/) very short, % length of cephalothorax, 7- 

 segmented. Segments 1 and 2 broad and short, segment 3, apparently 

 composed of two fused segments, with small conical process bearing 

 aesthetasc and several setae. Complete setation represented in 

 figure 95/. 



Antenna exactly as in adult female and not described here in detail. 



Mandible with well-developed praecoxal cutting edge, bearing 5 

 acute teeth and fine basal seta. Palp 2-segmented, with 4 apical setae 

 (fig. 95^). 



Maxillule (fig. 95h) with well-developed arthrite, bearing 4 ciu-iously 

 formed teeth. Rest of appendage strongly reduced, present as lobe 

 with 4 setae. 



Maxilla and maxillipede as in adult female, not to be described in 

 detail here. 



Legs 1 to 4 (figs. 95a-d) differing from those of adult female by 

 absence of jointing between 2nd and 3rd segments of exopodite and 

 endopodite. Number of setae and spinules as in adult stage, with 

 exception of endopodite of leg 2. In adult female setae on 2nd and 

 3rd endopodal segments of leg 2 number 7; in this stage, only 6. 



Leg 5 (fig. 95e) complete, shaped as male 5th leg figured by Nicholls 

 (1941, fig. 19). Baso-endopodite has 2 strong, spinulose spines. 

 Exopodite shghtly longer than broad, 2 of marginal setae thickened. 



Leg 6 (armature of genital plate) at this stage with only 2 setae (3 

 are figured for the adult male by Nicholls). 



I have described this specimen as an immature male because of the 

 development of the 5th legs; the segmentation of antennule and legs 

 make the Vth stage very likely. 



Adult female, total length 0.47 mm.; greatest diameter 0.26 mm.; 

 length of longest furcal seta 0.36 mm. 



