CHEMNITZIA. 419 
rounded sublanceolate points. The eyes are imbedded in the 
skin at the internal bases, but not quite so close together as 
in some other species.. Foot short, truncate im front, slightly 
notched in the centre, labiated, rounded behind when at 
rest ; somewhat elongated, though not much pointed, on the 
march; it carries the very light horn-coloured operculum of 
suboval form, with oblique strize of growth, on a simple upper 
lobe advanced to nearly the junction of the foot with the 
body. The foot has an inconspicuous central longitudinal line 
on the sole. 
It inhabits im sufficient abundance the littoral zone at Ex- 
mouth ; we have often taken in one search 100 live specimens ; 
it is, I believe, a strictly littoral species; those taken in the 
coralline district have turned out, on examination, slender 
young Chemnitzia acuta. 
Cu. unipEnTATA, Montagu. 
Odostomia unidentata, Brit. Moll. ii. p. 264, pl. 95. f.7, 8. 
Animal spiral, bluish hyaline-white. Mantle even with the 
shell. Rostrum on the march extended beyond the foot, 
compressed, bevelled at the margin, entire, truncate in front, 
varying less in figure than its congeners. Tentacula short, 
broad, awl-shaped, setose, blunt, with a fine transparent 
line through their centres. ‘The eyes are within the internal 
bases, close together, not raised, fixed on the connecting 
membrane. The foot is short, truncate, shghtly eared, but 
not in the least emarginate in front as in Chemnitzia acuta, 
or even hollowed-out like that of C. pallida, rounded poste- 
riorly, sloping to a broad, obtuse, lance-shaped terminus, and 
carries on the posterior upper surface of a scarcely perceptible 
operculigerous lobe, a ight corneous, suboval, simply striated 
operculum. The anterior portion of the sole of the foot is 
flake-white, the posterior hyaline, with a fine longitudinal line 
only in the centre of that part. The sole of the foot is divided 
from the upper pedal disk by a shallow groove, giving the foot 
a labiated aspect. 
This species differs little from C. acuta; the foot not being 
emarginate is the principal distinction, and the tentacula are 
2E2 
