IÓ9 



This species at first sight may easily be mistaken for Labidocera pavo Giesbrecht, of 

 which only the female is known. The genital segment of the female of Labidocera bataviae is 

 without the large protuberance that is so conspicuous in Labidocera pavo. The fifth pairs of feet 

 of the two females are also rather different in shape. 



Occurrence. — One hundred and fifty-six females and thirty males were obtained 

 from the plankton collected at the following stations. 



Stat. 16, 29 specimens. — Stat. 66, 22 specimens. — Stat. 71, 60 specimens. — Stat. 81, 

 26 specimens. — Stat. 98, 22 specimens. — Stat. 282, 27 specimens. 



7. Labidocera madurae nov. sp. Plate L, figs. 9 — 16. 



Female — length 2,5 mm. 



Seen from above, the body appears elongate ovate, and rather narrow. The cephalic 

 segment is without side hooks, and the forehead is boldly rounded. The last thoracic segment 

 is symmetrical. The lateral margins are produced posteriorly into pointed processes. The basal 

 part of the rostrum is wide. There is practically no excavation. The rami are long and are 

 distinctly articulated to the base (Plate L, fig. 10). 



The abdomen is short. It is composed of two segments. The combined length of the 

 abdomen and furca is contained five times in the total length of the cephalothorax \ from the 

 frontal margin to the distal end of the last thoracic segment. The genital segment is mode- 

 rately large. It is quite asymmetrical. The middle of the right side is considerably inflated. 

 The anal segment is very short. The furcal joints are symmetrical. They are rather longer 

 than broad (Plate L, fig. 9). 



The antennules are composed of twenty-three joints and extend to the end of the abdomen. 



The antennae, mandibles, maxillae and maxillipedes are similar to those of the previous 

 species. The apical portion of the second pair of maxillipedes is composed of four joints. 



The endopodites of the four pairs of swimming feet are two-jointed. The exopodites 

 are three-jointed. 



The fifth pair of feet is nearly symmetrical. The exopodite is furnished with two outer 

 marginal spines. The apex terminates in three subequal spines. The apex of the endopodite 

 is not bifurcate (Plate L, fig. 1 3). 



Male — length 1,9 mm. 



The male resembles the female except that the abdomen is composed of five segments. 

 The fourth and fifth segments are much shorter than any of the others (Plate L, fig. 141. 



The middle joints of the right antennule are only slightly swollen. The upper margin of 

 the proximal hinge joint and of the distal hinge joint is fringed with fine teeth (Plate L, fig. 15). 



The thumb-like process on the proximal end of the outer margin of the first joint of 

 the right exopodite of the fifth pair of feet, is comparatively short and curved. There is no 

 tooth at the base of the process as in Labidocera bataviae. The palm is simple. The claw-like 

 joint is long and narrow. The apical joint of the left exopodite is elongate ovate. It is twice 

 as long as broad. The outer margin is furnished with one spine, and the apex bears three 



spines. The inner margin has a pad of fine hairs. 



169 



SIBOGA-EXPEDITIE XXIX a. 



