560 DR THOMAS SCOTT ON THE 
Pseudothalestris assimilis, G. O. Sars, var. antarctica, nov. var. (PI. IX. figs. 5-9.) 
A single specimen—a male—closely resembling, if it be not identical with, the 
male of the species referred to, described by G. O. Sars in his Crustacea of Norway, 
vol. v. p. 141, was obtained in the same gathering with P. intermedia, collected in 
Scotia Bay, South Orkneys, Station 325, 60° 43’ 42” S., 44° 38’ 33” W. But though 
agreeing with some of the more important characters of that species, it differed in one 
or two minor points. In the first pair of thoracic legs the seta on the inner margin of 
the first of the inner ramus was situated nearer the proximal end of the joint. 
The inner produced portion of the basal joint of the fifth pair is narrower, and the 
second joint is broader, and further, this jomt is only provided with five instead of 
six sete (see fig. 8). On account of these differences, I am inclined to regard this as a 
variety of the species it otherwise so closely resembles. 
Fam. Drosaccip&. 
Genus Diosaccus, Boeck, 1872. 
Diosaccus tenuacornis (Claus). 
1863, Dactylopus tenuicornis, Claus, Die freileb, Copep., p. 127, pl. xvi. figs. 17-23. 
1880, Diosaccus tenuicornis, Brady, Monogr. Brit. Copep., vol. u. p. 68, pl. lix. figs. 12-16, pl. Ix. 
figs. 14-18. 
1906, Diosaccus tenuicornis, G. O. Sars, Crust. of Norway, vol. v. p. 146, pl. lxxxix. and xe. 
A single specimen—a male—was obtained in a tow-net gathering from Station 85, 
collected on 22nd December 1902, 28° 8’ 8., 39° 40’ W. 
Genus Amphiascus, G. O. Sars, 1905. 
Amphiascus fucicolus, new species. (Pl. IX. figs. 23-28.) 
Female.—Somewhat like Amphiascus similis (Claus) in general appearance ; 
rostrum prominent ; abdomen strongly flexed. Length about 0°8 mm. 
Antennules eight-jointed ; first and second joints robust and subequal; the next 
two shorter and not so much dilated ; the fifth and seventh joints are smaller than any 
of the others; the sixth is nearly as long as the fourth, while the last, which is narrow, 
is about equal in length to the third (fig. 28). 
In the first pair of thoracic legs, the outer ramus is considerably shorter than the 
inner one, and the middle joint is about twice the length of the first (fig. 26). In the 
fourth pair, the outer ramus is rather longer than the inner one (fig. 27). 
The fifth pair of legs are of moderate size and broadly foliaceous; the interior 
of the basal joint, which is only slightly produced, is provided with two short and 
three tolerably long slender hairs on the distal margin; the second joint has a sub- 
quadriform outline, the length being only a little greater than the width ; its distal end 
is obliquely truncated and furnished with five sete of unequal lengths—one near the 
