92 
summit; slightly arched, narrow, of nearly equal width till it 
slightly ‘widens at the everted front. Outer lip thickened and 
well-margined all round, smooth within. Columella with one 
strong oblique plait at the front, which is sueceeded on the pillar 
by seven transverse thread-like plaits; the columella-plait runs 
‘out to form the left i Pr v a shallow and wide effuse notch. 
Length, 1:6: width, - 
Tasmania; NW. PülterdT. ^ 
This species much resembles M. Jsseli, Nevill (M. ayn 
Braz. pk but it has more Eigen and the outer lip is smooth ; 
cymbalum, which is a much larger shell, it is more een 
ae. and the Piel of a different type. M. Hallii is 
truncated at the apex. M. alternans appears to resemble it, and 
though they have the same number of plications, yet their dispo- 
sitions are so distinctly different that we must regard them, in 
the absence of actual comparisons, as distinct. 
Marginella biplicata, spec. nov. 
Shell small, ed pellucid, straw-coloured. Spire very 
obtuse, of three and a-half whorls, scarcely exserted. Aperture 
narrow-elongate, seen to the front, obtuse-angled posteriorly. 
Outer lip scarcely thickened; not ascending on the spire, its 
he posterior one is slightly the stronger ; anterior emargination 
it^ di fined. 
Total length, 4; greatest width, 2 
Port Esperance, 'Tasmania ; in 94 fathoms, 2 exs. (W. L. May). 
It is nearest to M. tinilar but is shorter and relatively 
broader, and the apex is more obtuse, whilst the most prominent 
differences are in the smooth inner lip and biplicated columella. 
M Lini at Simsoni, spec. nov. 
M. denticulata (pars), Tate, non Conrad 
JM. minima, Petterd, non E 
Shell pyriform, contracted in front, shining, white. Spire 
immersed, though not wholly concealed. Aperture as long as the 
shell, slightly everted in the young. Outer lip thickened, smooth. 
Columella with about ten plications, decreasing gradually in size 
from ince front. 
, 1-9; greatest width, 1-3 mm. 
Tasmania and South Australia. 
minima, Petterd, the type of which we have studied has a 
length of 1:4 and a breadth of 1-0 mm., and besides being smaller 
han M. denticulata it is slightly more attenuated to the front, 
se the outer lip is not thickened ; differences which may be 
attributed to a young age. 
