MOLLUSCA.—HEDLEY. 55 
A single specimen, December 28th, 1913, from 288 fathoms, ooze, off the Mertz 
Glacier Tongue, Adelie Land, in South Lat. 66° 52° and East Long. 145° 30’. 
PONTIOTHAUMA ERGATA Sp. nov. 
(Plate VIII., figs. 85, 86, 87.) 
Shell large, thin and narrowly fusiform. Colour, uniform buff. Whorls of unknown 
number, contracted at the suture and flattened on the shoulder. Protoconch rather 
large, of two whorls, the first oblique, turbinate, the second vertical and radially striate. 
Sculpture : close spiral cords which increase from eight on the third whorl to 33 on the 
sixth. These are overrun in the line of growth by fine dense hair lines which describe 
a broad and rather deep sinus. Canal apparently short and open. Size unknown, 
the fragments suggest a length of from 80 to 100mm. 
This novelty is represented by two broken specimens. The first complete. from 
the apex to the fifth whorl in a length of 30mm., and thence broken; it was taken, 
January 28th, 1914, from 240 fathoms, ooze, off the Shackleton Ice-shelf, in South 
Lat. 65° 20’ and Hast Long. 95° 27’, and may serve as the type. The other is a fragment 
from the middle of a shell, consisting of a whorl and a half, and perhaps representing 
a ninth or tenth whorl; it was dredged December 28th, 1913, from 288-300 fathoms, 
ooze, off the Mertz Glacier Tongue, Adelie Land, in South Lat. 66° 55’ and East Long. 
145° 21’. 
Sipho gain Lamy,* taken in 230 fathoms, off the South Shetlands, is very like this, 
and, perhaps, is identical. It seems, however, to differ by being broader in proportion 
to the length, by having a sharper apex, and especially by having the columella margin 
recurved. 
HUSITRITON AURORA sp. nov. 
(Plate VIIL., figs. 88, 89, 90.) 
Shell thin, subtranslucent, ovate-lanceolate, with mucronate apex, rounded whorls, 
evanescent varices, and no radial sculpture. Colour: shell white under a thin buff 
epidermis save for an ochreous yellow band on the columella callus and within the lip. 
Whorls tumid, rather rapidly increasing, wound obliquely, four and a turret protoconch ; 
the latter of four smooth whorls, the third and fourth of which are almost the same 
diameter. Suture running in a groove. Sculpture: on the last whorl about 45, on 
the penultimate about 16 narrow, evenly spaced, raised, spiral cords, frequently with 
finer interstitial threads. Radial sculpture confined to faint growth lines, varices 
evanescent, represented by a notch at the suture and a double impressed line. 
Aperture pyriform, oblique, slightly sinuate at the shoulder of the whorl, outer lip 
thin, scarcely everted ; inner lip marked by a substantial band of callus. Canal short, 
broad, open and slightly twisted. Operculum (fig. 90) with apical nucleus. Length, 
83; breadth, 35mm. 
* Lamy.—2nd Exped. Antarct. Eranee Moll., 1911, p- 7, pl. i., figs. 7-8. ETRE nam 
