310 DR THOMAS SCOTT ON THE 



the end one is only about half the length of the preceding joint; inner ram us con- 

 siderably longer than the outer, and the first joint, which is as long as the entire outer 

 ramus, is widest near the proximal end, but becomes narrower distally ; the greatest 

 width is equal to about two-fifths of the length ; second and third joints are small ; the 

 last is provided with one or two apical setse, and a moderately stout appendage which 

 terminates in a small hook-like process (fig. 4). The fourth pair are small, and the 

 inner ramus is shorter than the outer one ; both rami are furnished with moderately 

 long and slender marginal seta;, and the terminal setse are also considerably elongated. 



Fifth pair small ; basal joint not greatly produced interiorly, the interior part 

 broadly rounded and provided with five elongated setae ; the space between the outermost 

 seta and the next one is rather greater than that between the others ; second joint 

 subtriangular, and furnished with one seta on the inner margin, two setee on the outer, 

 and two at the apex (see fig. 29, PI. IX.). 



The male does not differ greatly from the female, but the basal joint of the fifth pair 

 of thoracic legs is only slightly produced interiorly, and bears two instead of five setse, 

 while the second joint has three instead of two setse on its outer margin (fig. 6, PI. III.). 



Habitat. Scotia Bay, South Orkneys; collected in June 1903; Station 3'25, 

 60 43' 42" S., 44 38' 33" W. 



Remarks. This Antarctic Idomene so closely resembles the form described by 

 PHILIPPI from the Mediterranean that I have scarcely any hesitation in referring it to 

 the same species. The only difference of any importance is the small hook-like process 

 at the end of the inner ramus of the first pair of thoracic legs. The occurrence of this 

 species in the Antarctic collections made by the S.Y. Scotia is of considerable import- 

 ance. The distribution of Idomene extends to the British and Norwegian coasts. 



Genus Dactylopusia, Norman, 1903. 

 Dactylopusia frigida, new species. (PI. II. figs. 19-25.) 



Female. Body moderately stout, and somewhat similar to Dactylopusia neglecta, 

 G. 0. Sars, in its general appearance. Length, 0'85 mm. 



Antennules moderately short and composed of nine joints ; the first four are stout 

 and subequal ; the sixth is about equal to the fourth, and rather longer than the pre- 

 ceding joint ; the seventh and eighth joints are very short, but the terminal joint is 

 about equal in length to the fifth. Antennse small ; outer ramus moderately elongated 

 and composed of three joints, but the middle joint is very small. 



Second maxillipeds with the end joint oblong and furnished with a tolerably long- 

 slender claw. 



In the first pair of thoracic legs the inner ramus is moderately elongated and 

 narrow, but the outer is short and only reaches to a little beyond the middle one ; the 

 second joint is nearly twice as long as the first, and the end one is very small. The 

 next, three pairs are tolerably stout ; in the fourth pair the short inner ramus is some- 



(ROY. soc. EUIN. TRANS., VOL. XLVIII., 556.) 



