78 
AUSTRALASIAN ANTARCTIC EXPEDITION. 
A. MARGINATA V(tT. nOV. MC LEANI. 
(Plate 8, fig. 90.) 
This variety differs from the species in having in some of the anterior neuropods 
an additional partial row of 3, 4, 5, or 6 black spines, starting from below and extending 
upwards behind the third row. In this respect it recalls the arrangement seen in 
A. oMini Elders (1901), which, however, possesses 10-20 of these spine-bearing segments 
in place of 13 or 14 in A. marginata. 
It is true that Elders (1913, p. 521), in referring to a form of Aricia from the 
Falklands Islands differing from A. marginata in having 17 such segments, expresses the 
opinion that differences in the number of anterior segments, as well as of gill-less segments, 
are not of importance in differentiating species in the genus. If this is the case, it is possible 
that A . oUini is synonymous with A. marginata, which agrees in most features with it, 
though, according to Elders, the position of the gill in relation to the parapod is different, 
for in A. oldini it is closer to the dorsal cirrus, or “ lip,” than in the other species; and 
the form of the hinder parapods apparently present certain differences, though the 
figures given by Gravier (1911, pi. VI, figs. 72-73) for A. oldini are quite different from 
those given by Ehlers. 
Eor the present it seems better to regard the two species as distinct, though it is 
clear that they are closely allied, and this new variety emphasises this alliance. 
The additional row of spines does not exist on all the neuropods; usually they 
commence on the 3rd or 4th, and continue to the end of the series. In some cases the 
third normal row is imperfect at its lower end, but not always, even in the same individual. 
The gill commences on the 6th cluetigerous segment, though in one individual it is 
on the 7th, but variation in this respect is already known; and I note, for instance, that 
in one specimen of A. marginata the gill is present on the 5tli on one side, and on the 6th 
on the other. 
Some of the specimens are white, others are very pale brown. 
The general dimensions and other external features are similar to those in the 
species. 
Locality .— 
Commonwealth Bay, 25 fathoms (several). 
Genus Scoloplos Oersted. 
SCOLOPLOS MAWSONI Sp. UOV . 
S. kerguelensis Gravier (nec McIntosh) (1911), p. 108, pi. V, figs. 60-63. 
(Plate 8, figs. 91-94.) 
A vast number of individuals of this small species was collected at Boat Harbour 
at depths of 2-4| fathoms. In one bottle there are scores, if not hundreds of specimens. 
