1919. ] N. ANNANDALE & B. PrasHap: Mollusca. 25 
The shell is small, ovato-conical, short, broad and obese, with 
five whorls, fairly thick but naturally quite colourless and hyaline, 
rapidly, however, becoming milky after the death of the animal, 
polished and ornamented with delicate longitudinal striae on the 
surface. ‘The suture is impressed and very oblique, so that the 
spire is much longer in dorsal than in ventral view. The whorls 
increase rapidly in size and are highly convex; they are flattened 
outside the suture but rounded externally. The apex is minute 
but blunt and flattened. The basal whorl in ventral view is at 
least nearly three times as long as the spire, but these proportions 
are variable The mouth is large and somewhat expanded, ob- 
lique, never much longer than broad, ovate, rounded or bluntly 
pointed above and broadly rounded below. The peristome is con- 
tinuous and there is a band-like callus on the inner lip. The 
outer lip is hardly thickened, but distinctly though slightly 
flattened and very narrowly retroverted; its inner corner is sub- 
angulate. The umbilicus is rimate and the columellar callus is 
expanded over it. The columella is straight. 
Measurements of Shells (in millemetres). 
A BB” Coppa: F 
Length af 105 8°27 Oaeemns 38 
Breadth 42>, 5:2 Ort Ae ee 2°7 
enagrivolumouth ~... 275: 3° 13:7) 32es2 ame 
Breadthormouth .. “2, =2°6 2:6 273592 I'5 
The operculum, which cannot be retracted into the shell, is 
when fresh of glassy transparency. It has three whorls. The 
nucleus is situated some distance from the antero-internal border, 
The shape is ovate, broadly rounded anteriorly and bluntly pointed 
posteriorly. 
The radula is of the type normal in Ammnicola, s.s. The cen- 
tral tooth is small and transverse, produced at each side into a 
bluntly pointed, narrow process, which points downwards and a 
little outwards. The disk bears a large quadrate raised area and 
a series of basal denticulations at each side, remote from both 
the lateral and the basal margin. In each series there are two 
distinct denticulations and an obscure, imperfectly developed ex- 
ternal one. The upper margin of the tooth is slightly concave. The 
central cusp is enlarged and there are several smaller denticula- 
tions on each side of it; all are triangular, at least as long as broad 
at the base, and pointed at the tip. The lateral tooth is broad 
above but slender towards the base. It bears numerous small 
sharp cusps, the central one of which is slightly enlarged on the 
inner lateral. This tooth bears a broad blunt process on its disk 
and has its inner margin broadly and irregularly emarginate below. 
The outer marginal is very long and narrow, but broadens some- 
what at the base. Its cusps are very minute and sharp. 
The intromittent organ of the male is of relatively large size 
and distinctly flattened. Its external (right) margin is semi-circu- 
