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Bradyidius armatus T. Scott, 1 906(0), p. 298. 

 Bradyidius armatus van Breemen, 1908, p. 31, fïg. 31. 



Female — length 1,7 mm. 



The cephalothorax seen from above appears oval fusiform in outline, with both extremities 

 about equally narrowed. Viewed laterally it is seen to be moderately arched, with the forehead 

 obtusely truncated, and produced into a small bifurcate rostrum with divergent points. The last 

 thoracic segment is produced posteriorly into moderately strong spines, which scarcely reach 

 to the end of the genital segment. The combined length of the abdomen and furca is equal 

 to slightly less than one-third of the total length of the cepJialotJwrax, from the front margin 

 to the base of the genital segment. The genital segment is nearly as long as the combined 

 lenoth of the next three segments. The second segment is lon^er than the third. The third and 

 fourth segments are of nearly equal length. The furcal joints are about as long as the anal 

 segment, and are slightly longer than broad. The posterior margin of the genital segment is 

 furnished with a fringe of fine spines. 



The various appendages are similar to the figures given by Sars in the 'Crustacea 

 of Norway'. 



The 'Siboga' specimens differ from the Norwegian form in size, and in the length of 

 the spines of the last thoracic segment. Sars states that the spines reach beyond the genital 

 segment. I have compared the 'Siboga' specimens with examples found in plankton collected 

 in the Firth of Clyde, and with the exception of the smaller size, there appears to be no material 

 difference between theni. This can be seen on comparing the figures now given, with those in 

 the 'Sixteenth Annual Report of the Fishery Board for Scotland' (1898). Dr. R. N. Wolfenden 

 records a form obtained from plankton collected around the Maldives, under the name Bradyidius 

 armatus, which is probably identical with the species now figured. Wolfenden's specimens were 

 even smaller than those obtained from the 'Siboga' plankton, but unfortunately no figures are 

 given by that author, to enable a comparison to be made. 



This species was only represented by three specimens in the plankton collected during 

 the traverse of the 'Siboga'. The specimens were obtained at the following stations. 



Stat. 141, HENSEN vertical net, 1500 metres to surface, 2 specimens. 

 Stat. 276, HENSEN vertical net, 750 metres to surface, 1 specimen. 



Genus jEtideopsis Sars, 1903. 



The genus ^Etidcopsis approaches ^Etideus in general appearance, but is easily distinguished, 

 by the fourth and fifth thoracic segments being completely separated. 



Only one species is known. Specimens not diftering materially from the description and 

 figures given by Professor G. O. Sars were found in the 'Siboga' plankton. I have, therefore, 

 placed them under ^Etidcopsis rostrata for the present. 



1. ^Etidcopsis rostrata Sars. Plate V, figs. 13 — 24. 



-litidcopsis rostrata Sars, 1903, p. 160, pis. IV & V (suppl.). 

 .litidt-opsis rostrata van Breemen, 1908, p. 33, fig. 35. 



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