80 AUSTRALASIAN ANTARCTIC EXPEDITION. 
’n 7 others they are present on the 12th on one side, and on the 11th on the other. Six of 
them have quite small gills on the 11th segment on both sides. One has a gill on 11th 
on one side, and on the 13th segment on the other. 
Some of the above worms are sexually mature. But in some that are quite 
young, measuring only 5 mm., I find likewise that in some individuals the gills com¬ 
mence on the 12th on both sides, in others on the 11th, in others again on 11th and 12th. 
In one specimen of still smaller dimensions there is a very small gill on the 10th 
segment. 
We may, therefore, I think, regard the position of the first gill as being on the 
12th segment as a specific character. 
The anus is surrounded by a thickened smooth ring, slightly notched dorsally 
and ventrally; I see no distinct anal cirri in any of the many specimens examined. 
Localities .— 
Boat Harbour, Commonwealth Bay (collected by Dr. A. L. McLean), 2-4| 
fathoms. 
Distribution. —Near Port Lockroy (Gravier). 
Remarks. — This worm agrees well with that described by Gravier under the name 
of S. kergudensis McIntosh. At the same time he points out several features 
in which his worms differ from Hie account given by McIntosh, and he states 
“ that it is with doubt that I identify with that species the seven small 
Ariciens obtained from the Loosen Channel, Port Lockroy.” The shape of 
the dorsal and ventral “cirri” (or lips, as I prefer to term them) differs, 
as also does the shape of the gills, which McIntosh figures as filiform. Tt may 
be noted that McIntosh’s account and figures are not in absolute agreement 
as to the position of the gills. Gravier, following Ehlers, suggests that S. 
kergudensis may be the young of S. armiger. His specimens, which were 
but seven in number, were of small size, about 17 mm., and badly preserved, 
whereas mine are quite well preserved, and many are sexually mature. And 
since the gills commence almost constantly on the 12th segment, whereas 
those in S. armiger begin on the 15th-18th, and rarely as far forward as the 
lOtli, it is evident that this surmise is incorrect, at any rate for the species 
studied by me, and, as I have stated, these agree quite well with those 
described by Gravier. 
Recently, Fauvel (1916) has given a more detailed account of S. ker- 
guelensis, and finds some differences from that of the previous authors. But 
it is clearly different from the present worm, in that the gills appear on the 
18th-20th segment; he finds also certain peculiar chsetse—-forked, pectinate 
bristles—commencing on the 10th or 9th segment; these, as I have men¬ 
tioned, are not present, while on the 10th or lltli segment are one or two 
acicula, which are likewise absent from these worms. 
