548 DR THOMAS SCOTT ON THE 
The fifth pair are somewhat similar to those in Porcellidium ravane, both in their 
general outline and in having their extremity bluntly rounded (fig. 10). 
The abdomen and caudal rami also resemble the same parts in P. ravane, but 
in that species the caudal rami do not reach to the end of the fifth pair of feet, 
whereas in the present form the caudal rami reach somewhat beyond these appendages. 
They are also more bluntly rounded at the end, and the terminal and marginal spines 
are somewhat differently arranged, as shown in the drawing (fig. 12). 
Male.—The male, as is usual, is smaller than the female; the antennules are 
modified for grasping; the fifth pair of feet are different in form and armature, and 
the abdomen and caudal rami are shorter (see figs. 12 and 18). 
The fifth pair of feet are small, and narrow at the proximal end, but they become 
wider distally ; the extremity is obliquely truncated and fringed with about six short 
setiferous spines (fig. 11). Caudal rami are very short, and have the squarely 
truncated ends furnished with a few marginal setze (fig. 13). 
Habitat.—Scotia Bay, South Orkneys; collected in June 1903; Station 325, 
60° 43) 42S: 44°38 327 We 
Remarks. “his species, as already stated, has some resemblance to Porcellidiwm 
ravane, Thompson & A. Scott, but differs in several anatomical details, as, for example, 
in the structure of the female antennules, as well as in the form and armature of the 
caudal segments. It also resembles in some respects the Porcellidiwm wolfendem 
described by G. S. Brapy.* 
Genus Zisbe, Lilljeborg,t 1853. 
Tisbe austrina, new species. (PI. III. figs. 26-30.) 
Female.—This species, in its general appearance, is somewhat like Zisbe minor 
(T. Scott), but is rather more slender. Length about 0°6 mm. 
Antennules composed of eight joints; the second and third joints are subequal and 
of moderate size; the fourth is fully half as long as the third; the fifth and sixth, 
which are subequal, are together about as long as the fourth, but the seventh is very 
small; the end joint was incomplete, but appeared to be about as long as the fourth 
joint. The antennze are small, and the outer ramus reaches only to the end of the 
second joint of the inner ramus. Mouth organs somewhat similar to those in Tisbe 
minor, but the second maxillipedes are moderately stout. All the four pairs of 
swimming legs are also somewhat similar to those in the species mentioned. 
In the fifth pair, the inner portion of the basal joint ends in a blunt pointed apex, 
which bears two sete, one being moderately stout and elongated, and the other small ; 
* Deutsche Siidpolar Eaped., 1901-1903 : “ Uber die Copepoden der Stiimme Harpacticoida,” et seg., p. 556 (1910). 
Separate reprint. 
+ “The name Jdya having been previously given by BLAINVILLE to a genus of Acalephie,” was changed by G. O. 
Sars to Idyxa: see Rept. of Second Norwegian Arctic Haped. in the “ Fram,” 1898-1902, No. 18; Cructae by G. O. 
Sars, p. 21 (1909). Rev. T. R. R. Sreppine, in Annals of the South African Museum, vol. vi. p. 544 (1910), restores 
Lilljebore’s name, Tisbe. 
