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The endopodite of the first pair of feet is composed of three joints. 
The second, third and fourth pairs of feet are of the normal Pozxtel/a form. 
The fifth pair is moderately large. The thumb-like process on the proximal end of the 
first joint of the right exopodite is very long. It is curved inwards. The middle of the joint is 
provided with a nearly straight spine. The claw-like joint is long and slender and is much curved. 
It is furnished with two marginal spines and one apical spine. The last joint of the exopodite 
of the left foot bears three moderately strong apical spines. The inner margin has a large pad 
of fine hairs. The outer dorso-lateral margin is furnished with a small spine (Plate LIII, fig. 15). 
Female unknown. 
This species may easily be passed over as the male of Poztella securifer, as it resembles 
it in the possession of a circular lens in the base of the rostrum, and also of a serrate plate 
on the proximal hinge joint of the right antennule. The structure of the fifth pair of feet, 
however, is quite distinct. 
Occurrence. — Two specimens were found in the plankton collected with the HENsEN 
vertical net at Station 203, 1500 metres to the surface. 
Genus Labidocera Lubbock, 1853. 
The members of this genus are closely related to Pontella, but they can readily be 
separated by the structure of the first pair of feet. The endopodite of the first pair is two-jointed, 
like the endopodites of the second, third and fourth pairs of feet. The cephalic segment is 
usually without side hooks. One pair of dorsal eye lenses is present. The basal part of the 
rostrum has no lens. 
Seven species of Ladzdocera were represented in the plankton collected by the ‘Siboga’ 
in the Malay Archipelago. Two of the species do not appear to have previously been described. 
1. Labtdocera acuta (Dana). 
Pontella acuta Dana, 1849, p. 30. 
Pontellina acuta Dana, 1852, p. 1150, pl. 80. 
Pontella acuta Brady, 1883, p. 89, pl. XXXVI, figs. 1—12. 
Labidocera acutum Giesbrecht, 1893, p. 445, pl. 23, 25 & 41. 
Labidocera acuta T. Scott, 1893, p. 85. 
Labidocera acutum Giesbrecht, 1895, p. 250. 
Labidocera acuta Giesbrecht & Schmeil. 1898, p. 134. 
Labidocera acuta 1. C. Thompson, 1900, p. 282. 
Labidocera acutum Cleve, 1901, p. 7. 
Labidocera acuta A. Scott, 1902, p. 407. 
Labidocera acuta Thompson & Scott, IGOX, (Os Byit. 
Labidocera acutum Cleve, 1903, p. 363. 
Labidocera acuta Cleve, 1904, p. 191. 
Labidocera acuta Wolfenden, 1905 (a), p. 1016. 
Labidocera acuta van Breemen, 1908, p. 150, fig. 168. 
This species proved to be moderately common. It was widely distributed throughout the 
area investigated as shewn by the following records. 
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