36 
AUSTRALASIAN ANTARCTIC EXPEDITION. 
Chcetopleura savatieri Rochebrune, Miss. Scient. Cap Horn, vi., 1889, p. 135, pi. ix., fig. 
3. C. Jiahni, id. op. cit., p. 136, pi. ix., fig. 4. C.frigida, id. op. cit., p. 137, 
pi. ix., fig. 5. 
Plaxipliora superba Pilsbry, Man. Conch., (1), xiv., 1893, p. 319, pi. lxviii., figs. 55-61 ; 
Id., Suter, Man. N.Z. Moll., 1913, pp. 21, 1079 ; Id., Thiele, Zool. Chun., 1909, 
heft, lvi., p. 27, pi. iii., figs. 39-40. 
Plaxipliora subatrata Suter, Proc. Malac. Soc., ii., 1897, p. 190, text figs. 7-11, and 
Subantarctic Islands, N.Z., i., 1909, Moll., p. 3. 
Plaxipliora aucklandica Suter, Subantarctic Islands, N.Z., i., 1909, p. 2, pi. i., fig. 1. 
The intricate nomenclature of this species has been recently set out by Mr. Tom 
Iredale, who shows that this giant “ has the longest synonymy of any austral chiton 
and is yet the best marked species.” Continuity of its distribution from the Strait of 
Magellan and Cape Horn in the east to the southern islands of New Zealand in the west 
has been broken by the interposition of a frozen Antarctica. On Macquarie Island 
this enormous chiton seems to be generally abundant. Specimens are noted as collected, 
May, 1912, on rocks in littoral zone at Garden Bay, and again from the under surface 
of stones at low water near the north end. Some individuals preserved by Mr. H. 
Hamilton reach a length of 120mm. 
Class GASTEROPODA. 
Schism ope subantarctica sp. nov. 
(Plate V., figs. 54, 55.) 
Shell minute, very oblique, imperforate. Colour white. Whorls three, first two 
coiled in one plane, the last rapidly enlarging and obliquely descending. Sculpture : 
spire smooth, base ornamented with spaced spiral ridges decussated by finer and closer 
radial threads. On the upper part of the body whorl this sculpture is faintly repeated. 
The perforation is small elliptical, its major axis parallel to the spiral, distant rather more 
than a quarter of a whorl from the aperture, to which a fine seam connects it. The 
margins are upraised. Posterior to the perforation is neither fasciole nor groove, which 
constitutes one of the peculiar features of the shell. The aperture is ovate and oblique, 
its inner lip appressed to the imperforate axis. Maj. diam., ITS ; height, 0-75mm. 
One specimen, from a worm tube, collected January 19th, 1912, at Aerial Cove, 
Macquarie Island, by Mr. H. Hamilton. 
S. mouchezi Velain (Archiv. Zool. Exper., vi., 1878, p. 119, pi. iv., figs. 7, 8) is equally 
minute but is rounder, more strongly sculptured, and has a deep furrow behind the 
perforation. 
