8 EDGAR A. SMITH. 
in the middle, somewhat sinuated above and at the base; columellar margin thickened, 
reflexed, joined above to the outer lip by a thin callosity. 
Length, 5°75 millim. ; diam. 2; aperture, 1°5 long, 1 broad. 
Holes 9,12. In 25-51 fathoms. 
The whorls are more convex than in many of the known small species. /. amblia, 
Watson, from between Marion and Prince Edward Islands, has longer and flatter 
whorls, a longer aperture, and is smaller. 
ScALA ANTARCTICA. 
(Pl. L, figs. 10-10b.) 
Shell small, elongate, imperforate, dirty whitish, greyish towards the upper part of 
the spire; whorls 7-8, very convex, divided by a somewhat oblique suture, exhibiting 
fine lines of growth and thickened varices, one or two upon each whorl ; last whorl 
obtusely keeled around the base; apex blunt, globose; aperture roundly ovate ; 
peristome thickened and a little expanded. 
Length, 10 millim. ; diam., 3°5; aperture, 2°5 long. 
Hole 12. In 25-30 fathoms. 
Remarkable on account of the smooth, rounded whorls, and thickened varices. 
When closely examined, the dirty whitish colour is seen to be composed of numerous 
irregularly interrupted spiral and longitudinal lines, producing a minutely cancellated 
appearance (see fig. 10b). Operculum normal (fig. 10a), yellowish, horny, redder in the 
centre. 
RISSOIA ADARENSIS. 
(PI. IL, fig. 2.) 
Rissou adarensis, Smith, ‘Southern Cross’ (1902), p. 205, pl. xxiv., fig. 17. 
Shell elongate ovate, white, smooth, glossy, imperforate ; whorls 5, considerably 
convex, marked with fine striz of growth; apex large, globose, smooth ; suture a little 
oblique; aperture ovate; peristome continuous, outer margin a little thickened 
externally, columellar margin narrowly reflexed. 
Length, 3°3 millim., diam., 1:5 ; aperture, 1 long. 
Operculum thin, minute, ovate, paucispiral, a little concave above, without any 
process on the under side. 
Holes 4,12. In 25-41 fathoms. 
A pure white semi-transparent species, without any striking characters. Allied to 
R. georgiana, Pfeffer, from South Georgia, but different in form. The finer series of 
specimens obtained by the ‘Discovery’ shows that this species is sometimes a little 
longer than the type originally described, and may consist of five whorls. The trace 
of faint longitudinal costation referred to in my former description is produced by some 
of the lines of growth being more pronounced than others. issoa (Setia) columna, 
Pelseneer, is very similar. 
