MOLLUSCA.—HEDLEY. 33 
hinge of a Macquarie Island specimen together with the hinge (figs. 45, 46) of L. 
australis from New South Wales for comparison. The habits of an allied, if not identical, 
species on St. Paul Island are described by Velain.* 
Mr. H. Hamilton gathered this Laswa on Macquarie Island, on rocks between 
tide marks, associated with Gaimardia pusilla. 
CHIONE MAWSONI sp. nov. 
(Plate IV., figs. 47, 48, 49, 50.) 
Shell very solid, oblong ovate, umbo at about two-fifths of the length, varying 
both in contour, sculpture and colour. Externally the colour is a dull white, internally 
buff or a rich purple which may either stain the margin and the muscular impressions 
or be suffused over the whole interior. Sculpture ranging from a predominance of 
tadial to a predominance of concentric lines. Usually the surface is comparatively 
smooth for a distance of about 12mm. from the umbo where it is engraved by about 
120 fine, shallow, radiating grooves, parted by rather wider flat interspaces, crowded 
laterally and spaced medially. External to this area there may be a sudden change 
to coarse elevated, irregular, close-set, concentric cords, grouped by deeper furrows 
into bundles of four or five and each composed of an aggregate of smaller fibres. On 
the posterior dorsal region these cords rise higher. In another case the concentric 
sculpture in high relief is absent, the valve is comparatively smooth and radial striz 
prevail over the whole disk. 
Lunule long and narrow, limited by a deeply-incised groove. Sinus short, 
horizontal, and pointed. Length, 37; height, 29; depth of conjoined valves, 20mm. 
A second example is 40 x 32 x 19; and a third, 31 x 28 x 18. 
Of Mr. H. Suter I inquired if this was the species from the Auckland Islands which 
he described as Cytherea subsulcata. He replied that the C. subsulcata differed by being 
more rounded with a more coarse sculpture which extended to the umbo, and that the 
Macquarie shell was new to him. Venus antarctica Velain, from St. Paul,} is a much 
rounder shell than this. 
7 Twenty-six specimens were dredged, December 4th, 1913, in 14 fathoms, sandy 
bottom, in Lusitania. Bay, Macquarie Island. 
SAXICAVA ANTARCTICA Philippi. 
(Plate IV., fig. 51, 52, 53.) 
Saxicava antarctica Philippi, Archiv. f. Naturg., 1845, p- 52; Jd., Smith, Proc. Zool. 
Soc., 1881, p. 40; Jd., Martens and Pfeffer, Jahrb. Hamburg Wiss. Anst., iii., 
1887, p. 113, pl. iv., fig. 2; Jd., Rochebrune, Miss. Scient. Cap Horn, Moll., 
* Velain.—Archiv. Zool. Expér., vi., 1878, p. 136. ¢ Velain.—Arch. Zool. Expér., vi., 1878, p. 138, pl. v., figs. 21, 22.: 
Vol. 1v., Part 1—xr 
