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furcal joints is contained nearly twice in the total length of the cephalothorax, from the frontal 
margin to the distal end of the fifth thoracic segment. The genital segment is moderately 
long and is considerably inflated at the proximal end. It is equal to the combined length of 
the next three segments added to half the length of the furcal joints. The second and fourth 
segments are sub-equal in length. The third segment is equal to two-thirds of the length of 
the second segment. The furcal joints are slightly longer than the anal segment. The joints 
are furnished with two outer marginal setae and three apical setae (Plate LXIX, fig. 1). 
The antennules are rather long and seven-jointed. The joints are all of moderate length, 
except the first and third, which are shorter than the others. (Plate LXIX, fig. 2). 
The antennae are short, stout and four-jointed. The apex of the fourth joint is furnished 
with two stout curved claws and four setae (Plate LXIX, fig. 3). 
The apex of the mandible is stylet-shaped. The basal portion is of moderate size, but 
it is deeply constricted in the middle. The upper margin is finely serrate (Plate LXIX, fig. 4). 
The maxillae are short and broad. They are furnished with one marginal and three 
apical setae. 
The apex of the first pair of maxillipedes is stylet-shaped. The upper margin is coarsely 
Setraten delatem le OG ihions =5)): 
The second pair of maxillipedes is small and two-jointed. The second joint terminates 
in one very stout claw. The upper surface is provided with two short spines (Plate LXIX, fig. 6). 
The exopodites and endopodites of the first three pairs of feet are three-jointed. The 
exopodite of the fourth pair of feet is three-jointed. The endopodite is one-jointed. The outer 
margin is sharply constricted in the middle. The apex is furnished with two moderately long 
spathulate spines (Plate LXIX, fig. 7). 
The fifth pair of feet is slender and of moderate length. The apex of each foot bears 
two short spines. 
Male unknown. 
This species is readily recognised by the elongate body, by the moderately long and 
inflated genital segment, and by the proportional length of the joints of the antennules. 
Occurrence. — [wo specimens were obtained from the plankton collected during the 
night at Station 142, when the ‘Siboga’ was anchored off Lawui, on the Coast of Obi Major. 
4. Pseudanthessius obscurus nov. sp. Plate LXIX, figs. 8—14. 
Female — length 1,15 mm. 
Seen from above, the body appears elongate and narrowly ovate. The frontal margin 
is narrowly rounded. It is almost angular in outline. The fourth thoracic segment is short and 
is very slightly produced posteriorly. The distal ends are rounded. The fifth thoracic segment 
is broadly triangular in shape with the distal end moderately expanded. 
The abdomen is slender and is composed of four segments. The combined length of 
the abdomen and furcal joints is contained one and two-third times in the total length of the 
cephalothorax, from the frontal margin to the distal end of the fifth thoracic segment. The 
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