COPEPODA. 23 



6. S. LONGIPES. 

 S. longlpes, Giesbrecht, ' BelgicS, ' Eep., p. 20. 



Cephalo thorax symmetrical ; genital segment swollen laterally and roughly 

 triangular-shaped, anterior antennae not reaching end of thorax, no spines on genital 

 segment ; fifth feet in 9 last segment elongated, curved (foliate), with external spine 

 half as long as in ^ ; right foot with two middle segments very elongated, ending 

 distally in curved hook not articulating ; left foot without tumefied segment, two 

 middle elongated, last shorter with knob and spine, but no processes. Size 'S-'Q m. 

 (Antarctic). (' Discovery ' and ' Gauss ' collections. Wolfenden.) 



7. S. ANTARCTICUM. 



Eobust, cephalothorax a little unsymmetrical, right side prolonged; genital segment 

 swollen laterally, with bunch of spine-like bristles each side ; furca as broad as long ; 

 anterior antennae reach to Ab. 2 ; Be of posterior antennae longer than Hi. Fifth feet 

 in ? right side longest, each with three end spines, innermost hook-like ; in ^ , 

 right with third joint elongated and club-shaped distally, with a large, roughly 

 triangular plate, and last joint a strong, curved hook ; left foot, no tumefied segment, 

 and last joint with distally a short-stalked haired knob, no appendages. Size = 175-2 

 mm. ( ' Discovery ' collection. ) 



StEPHUS LONGIPES. 



(Plate v., figs. 1, 2, 3.) 

 Stephus longipes, Giesbrecht. ' Belgica ' Rep., p. 20. 



? "75- "80 mm. <f '65-70 mm. Cephalothorax rather more than twice as long as 

 the abdomen ; head separated from first thoracic segment, but all segments very 

 difiicult to determine, owing to the indistinctness of the lines. Last thoracic segment 

 with rounded margins and symmetrical. Abdomen in the female four, in the male five 

 segments, furcal segments only as long as the anal, as broad as long, and with rounded 

 margins, each with four tail bristles and a short fifth inner marginal bristle. Genital 

 segment in the female as long as the next two, laterally with roughly triangular 

 swellings, and in its greatest breadth, broader than long. Anterior antennae not as 

 long as the thorax, and of twenty-three joints, the first, second, eighth and ninth 

 coalesced, with few bristles, the longest on the seventh and eighteenth joints, but well 

 supplied with long aesthe tasks. 



Posterior antennae with exopodite about one-third longer than the endopodite. 

 Posterior foot-jaw with rather thick first basal and B I: B2: Ri&s % -.7 : Q ; mandibles 

 with broad-ended masticatory plate, one pointed outer tooth, with considerable space 

 between it and the middle stout comparatively broad teeth, and three pointed inner 

 teeth. 



