2 2 2 



31. Family Canthocamptidae. 

 Genus Ameira Boeck, 1864. 



The members of this genus can be distinguished by the long slender antennules, by 

 the long slender three-jointed endopodite of the first pair of feet, by the much shorter three- 

 jointed exopodite, and by the perfectly smooth anal operculum. 



One species apparently belonging to this genus as re-defined by Sars in 'Crustacea of 

 Norway' Vol. V, was obtained from the plankton collected by the 'Siboga' in the Malay Archipelago. 



1. Ameira sibogae nov. sp. Plate LX, figs. 1 



'/ • 



Female — length .43 mm. 



Seen from the side, the body appears moderately slender and rather cylindrical. The 

 cephalic segment is large and is nearly as long as the combined length of the first three thoracic 

 segments. The rostrum is small and inconspicuous. 



The abdomen is composed of four segments. The genital segment is comparatively large 

 and is equal to the combined length of the second and third segments. It is traversed by a 

 well defined suture. The anal segment is short. The operculum is very small and is perfectly 

 smooth. The furcal joints are short. The joints are as long as broad and are equal to about 

 half the length of the anal segment (Plate LX, fig. 7). 



The antennules are long and slender and are composed of eight joints. The last joint 

 is distinctly smaller than the others. The fourth joint is furnished with a long sensory filament. 



The antennae are very small. The exopodite appears to be indistinctly two-jointed (Plate 

 LX, fig. 3). 



The mandibles, maxillae and maxillipedes are nearly similar to those of Ameira 

 longipes Boeck. 



The exopodites and endopodites of the four pairs of feet are three-jointed. The endo- 

 podite of the first pair of feet is much longer than the exopodite and is distinctly prehensile. 

 The first joint is equal to twice the combined length of the second and third joints. The inner 

 marginal seta is placed in the distal third of the joint. The last joint is rather narrow and 

 linear in shape. It is two and a half times longer than the second joint. The apex is furnished 

 with one straight claw and a geniculate seta (Plate LX, fig. 5). 



The fifth pair of feet is of moderate size and two-jointed. The proximal joint is wide 

 at the base and only very slightly attenuated towards the apex of the inner expansion. The 

 apex bears four moderately long setae. The distal joint is narrow and is somewhat pyriform 

 in shape. It is furnished with three outer marginal setae, one apical seta, and one seta at 

 the distal end of the inner margin (Plate LX, fig. 6). 



Male unknown. 



This species can readily be distinguished by its very small size, by the proportional 

 length of the joints of the endopodite of the first pair of feet, and by the shape and armature 

 of the fifth pair. 



