2 I 2 



Male unknown. 



This small species can readily be identified by the very narrow distal portion of the 

 fifth pair of feet, and by the slender condition of the whole of the outer marginal setae. 



Occurrence. — One specimen was found in the washings from dredged invertebrata 

 collected at Station 226, at a depth of 1595 metres. 



Genus Parapeltidium nov. 



The body is comparatively short and greatly depressed. The exoskeleton is highly 

 chitinised. It is also strengthened with broad anastomosing bands of chitin. The cephalic seg- 

 ment is very large and expanded. The rostrum is large and moderately prominent. The thoracic 

 segments are slightly produced. The genital segment is large and strongly chitinised. The other 

 abdominal segments are short. The antennules are short and five-jointed. The antennae, man- 

 dibles, maxillae and second pair of maxillipedes are similar to those of Pcltidium purpureum. 

 The first pair of maxillipedes is similar to that of Altcutha dcpressa. The terminal joint is of 

 moderate length and ends in a short claw. The exopodite of the first pair of feet is slender 

 and is three-jointed. The endopodite is two-jointed, but the basal joint is not expanded as in 

 Pcltidium. The second, third and fourth pairs of feet are similar to those of the genus Pclti- 

 dium. The fifth pair of feet consists of a single, highly chitinised, spiniform joint. 



This genus is closely related to Pcltidium in the possession of the anastomosing chitinous 

 bands, but the whole exoskeleton is much stronger and more flattened. The slender endopodite 

 of the first pair of feet and the one-jointed spiniform fifth pair, readily separate this genus 

 from Pcltidium. 



One species was represented in the plankton collected by the 'Siboga' in the Malay 

 Archipelago. 



The absence of a division between the proximal and distal parts of the fifth pair of 

 feet of the three genera, Eupelte, Altcuthella and Parapeltidium, appears to be of some 

 importance. This character readily separates these genera from the members of the family 

 Peltidiidae, as defined by Professor G. O. Sars in 'Crustacea of Norway' Vol. V, page 61. It 

 may be found necessary, therefore, at some future period to establish a separate family for 

 their reception. 



1. Parapeltidium johnstoni nov. sp. Plate LXV, figs. 1 — 5. 



Female — length 1.36 mm. 



Seen from above, the body appears very wide and depressed. It is oval in outline. The 

 cephalic segment is large. The distal ends are expanded and are produced beyond the ends 

 of the first thoracic segment. The greatest width is at the end of the cephalic segment and 

 is equal to two-thirds of the entire length of the animal. The distal ends of the cephalic and 

 thoracic segments are pointed. The segments are produced dorsally in the middle line into 

 triangular projections. The rostrum is moderately large and prominent. The frontal margin is 

 truncate. The genital segment is large and is deeply indented in the middle. The distal ends 



