312 PROCEEDINGS OF THE MALACOLOGICAL SOCIETY. 
with a dark shade over the extremity of the foot, commencing just 
behind the visceral mass, where the keel rises, and extending diagonally 
to the mucous gland ; this shade of colour is intensified along the line 
of the keel just ; below the pale margin, and again on the lower margin. 
The upper surface of the mantle is pale grey. The peripodial margin 
is of the same colour as the rest of the body, with three grooves above 
it (Fig. 1¢;. see also (2) pl. xi, fig. 6, and (3) pl. Ixxin, fig. 47). 
The visceral sac is situated well forward, and the mantle completely 
covers the shell. There is a raised bank-like ridge on the night 
posterior margin, commencing just behind the respiratory orifice, con- 
tinuing round to the back of the visceral mass, and meeting another on 
the left side. Between these right and left ridges, the shell area is 
flattish, and a shght median fold is seen in the centre of it. On cutting 
and turning back the mantle the extremely thin membranaceous 
rudimentary shell is exposed to view, and the apex of the visceral sae 
is seen through it (Fig. 1). In this specimen the shell did not extend 
beyond this in a posterior direction, and there was, therefore, not the 
slightest indication of an apex to the shell. 
The eye and oral tentacles are well seen; in this spirit specimen the 
mouth (Fig. 1¢) is extended and protruded forward, disclosing the jaw, 
and is surrounded by a circle of globose tubercles. In Fig. Te are also 
shown the three peripodial grooves, which are not easily made out near 
the extremity of the foot, owing to some loss of the surface in the 
spirit. 
The buccal mass is spherical, the radula very broad, and under 
a moderate power of a beautiful delicate gauzy texture. Further 
examination shows an enormous number of close-set, elongate teeth, 
all very similar in shape, in each row (Fig. 19), only differing by 
becoming shorter towards the margin, the formula being :— 
204 : 1: 204. 
The centre tooth is evenly tricuspid, long, and narrow, the laterals are 
evenly bicuspid, the outer cusp being slightly the larger, the outermost 
teeth are evenly tricuspid. The jaw (Fig. 1/) is straight in front, with 
a slight concavity in the middle. 
Untor tunately, 1 did not secure the generative organs complete. 
The penis was broken off, as also was the spermatheca. The amatorial 
organ (Fig. 1d) remained with the oviduct and part of the vas deferens. 
The form of the amatorial organ is like that of Damayantia Smithr; it 
is bent on itself, and the calcareous dart was found. What is seen 
agrees with the corresponding parts found in former dissections of that 
1 With regard to these two sets of drawings, there is this difference to be noted 
between them: those on plates Ixxiii-lxxv, ‘‘ Land and Fresh-water Mollusca 
of India,’’ are my original drawings, made on autographic paper at the time 
the dissections were in hand, and eyentually transferred to stone; those on 
plates xi—xiv in the Proe. Zool. Soc. were copied from them and put on stone by 
Mr. Smit—they have lost a little owing to the fact that this draughtsman was 
not acquainted with the subject he was drawing and did not have the dissections 
before him. All the figures on plate ]xxiii are trom the specimen of Damayantia 
Smithi, and the generative organs (figs. 7-7d) compare well with the drawings 
made by Mr. Collinge (pl. xi, figs. 9, 10) from his dissections. 
