550 DR THOMAS SCOTT ON THE 
end joint of the outer ramus is about twice as long as the preceding joint. It is also 
moderately narrow, and furnished with two rather stout marginal spines and two at 
the apex, the inner apical spine being Sane as long as the joint to which it is 
articulated (fig. 27). 
The fifth pair are somewhat like the same pair in Tisbe gracilis ; the second joint, 
however, differs in being rather wider in proportion to its length. The seta on its 
inner margin is also articulated nearer the middle of the joint, and the whole of the 
inner aspect of the joint is covered with minute hairs (fig. 28). 
Halbitat.—Scotia Bay, South Orkneys; collected in June 1903; Station 325, 
60° 43’ 42” S., 44° 38’ 33” W.. Rare. 
Remarks—This form resembles Jdyxa gracilis, and might be considered as only 
a variety of that species, but the inner ramus of the first pair of swimming legs is 
proportionally and distinctly more elongated, and the second joint of the fifth pair is 
also more broadly ovate. Because of these differences and one or two others alluded 
to in the description, the species ought, I think, to be considered distinct. 
Genus Psamathe, Philippi, 1840. 
Psamathe longicauda, Philippi. (PI. V. figs. 16-22.) 
1840, Psamathe longicauda, Philippi, Archiv f. Naturgesch, (1840), p. 89, pl. iv. fig. 1. 
1866, Scutellidium tisboides, Claus, Die Copepoden fauna von Nizza, p. 21, pl. iv. figs. 8-15. 
1880, A 5 Brady, Monogr. Brit. Copep., vol. ii. p. 175, pl. Ixviil. figs. 1-10. 
1905, Psamathe longicauda, G. O. Sars, Crustacea of Norway, vol. v. p. 83, pl. xlix. 
A single specimen of this Harpactid was obtained in a plankton gathering collected 
at Station 27 in 18° 38’ N., 25° 09’ W. 
The body in this species is considerably flattened, and there is a distinct break 
between the anterior and the posterior portions, best seen when viewed from above, 
the former being expanded, while the latter is narrow (see fig. 16). 
The antennules are composed of nine joints ; the first three are elongated and moder- 
ately stout, and are together about twice the entire length of the remaining six joints: 
the end joint is slender and rather longer than the three preceding joints combined 
(ie, 7"): 
Antennee with the outer ramus four-jointed and not more than half the length of 
the inner one; it is also articulated to the outer distal angle of the second basal joint 
(fig. 18). 
Maxillipeds moderately stout; first pair smaller than the second and armed with 
two claw-like terminal spines (fig. 19). Second maxillipeds robust; the basal joint is 
provided with a stout plumose seta on its inner distal angle, and the end joint with 
three stout terminal claws and a small plumose bristle (fig. 20). 
The first pair of thoracic legs are moderately stout, and both rami are composed of 
three joints, but the end joints are extremely small and bear peculiar recurved terminal 
