ENTOMOSTRACA OF THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 555 
the spine, which spring from near its distal end, while the inner margin of the same 
joint and the outer margin of the inner ramus are both fringed with delicate hairs, as 
shown in the drawing (fig. 24). Another feature here is the presence of three small 
teeth on the transverse end of the first joint of the outer ramus (see fig. 24). 
The next three pairs are somewhat similar in structure to the same appendages in 
Parathalestiris yacksont (‘T. Scott). 
The fifth pair are tolerably large and foliaceous ; the outer segment, which is broadly 
ovate in form, is provided with six sete; five of them spring from the distal half of the 
outer margin and apex, and one from the lower part of the inner margin; the upper- 
most three on the outer margin are moderately stout and widely apart, while the two 
at the apex are slender and close together. The inner portion of the basal joint is 
shorter than the outer, and is somewhat triangular in outline, being broad at the 
proximal end, and tapering from thence to the rounded extremity ; five sete spring from 
the distal end of this inner segment ; the three on the inner aspect are moderately stout 
and placed widely apart ; the other two spring from the lower half of the outer margin 
and are close together ; they are smaller than the others (fig. 25). 
Habitat.—Scotia Bay, South Orkneys; ¢ollected in June 1903; Station 325, 
60° 43’ 42” S., 44° 38’ 33” W. Only one or two specimens were observed. 
Remarks.—The species now deseribed is in its several appendages not unlike the 
northern form mentioned above, the fifth pair of thoracic legs being remarkably 
similar ; there are, however, a few differences of more or less importance between them 
—the species referred to being, for example, distinctly larger, and the caudal rami 
entirely different. 
Genus Jdomene, Philippi, 1843. 
Idomene forficata, Philippi. (PI. III. figs. 1-6; Pl. IV. fig. 1; Pl. IX. fig. 29.) 
1843, Idomene forficata, Philippi, Archiv f. Naturgeschichte, p. 65, pl. iii. fig. 4. 
1880, Dactylopus flavus, Brady, Monogr. Brit. Copep., vol. 11, p. 116, pl. lvi. figs. 1-11. 
1906, Idomene forficata, G. O. Sars, Crust. of Norway, vol. v. p. 134, pl. Ixxxii. 
Female.—Body somewhat depressed, expanded in front, but becoming narrower 
towards the distal end. Length, 57 mm. 
Avtennules short and composed of seven joints; the first four joints are tolerably 
large, but the others are smaller, the penultimate joint being rather shorter than the 
preceding one, and about half as lone as the next. Antennz with the outer ramus 
small and biarticulate. 
The second maxillipeds are of moderate size; a stout seta springs from the end of 
the first joint, while the second is armed with a long slender claw, and a small bristle 
also springs from near the distal end of its inner margin. 
The four pairs of swimming feet have both rami three-jointed. ‘The first pair are 
stout, and the second basal joint is furnished with a stout seta on both the outer and 
inner margins ; the first and second joints of the outer ramus are tolerably large, but 
