1873.] F. Stoliczka — Land-shells of Penang Island. 19 



The animal is slender and very long ; when fresh the extended foot 

 is three times the longer diameter of the shell, which is then entirely covered 

 by the mantle ; but in captivity the shell lobes shrink very rapidly, being 

 reduced to narrow linguiform appendages. Middle of back and of the 

 hind foot whitish or very pale brownish, with a slight pinkish tinge ; a 

 broad blackish band runs from each pedicle along the sides of the whole 

 back, and also on the sides of the posterior part of the foot, as far as 

 the terminal gland, which is superseded by a very distinct pointed horn ; 

 the dark colour extends down to the pedal row, while a large black spot 

 about the middle of the foot on each side reaches down to the sole ; 

 pedicles long, grey ; tentacles short and almost white ; mantle blackish with 

 small whitish dots. All the four mantle lobes are well developed, the left 

 shell and neck lobes are proportionately somewhat larger than the correspond- 

 ing right ones, and each of the former has a deep but narrow incision in its 

 lower portion. 



The jaw is about one mill, broad, quadrant shaped, smooth, without any 

 projection in the centre of the concave edge, like in most other species of 

 the genus. 



The radula is moderately broad and nearly 2*5 m.m. long ; there are 

 95 transverse rows and about 121 teeth in each row, all remarkably small 

 and from the tenth tooth they somewhat rapidly decrease in size towards the 

 edges. The centre tooth has two distinct denticles on either side and a 

 third much smaller one nearer to the base ; the principal cusp is pointed. 

 On the subsequent teeth the inner denticles disappear first, and gradually 

 altogether, then the lower outer, while the upper outer remains, until at 

 last it equals the principal cusp, so that the outermost teeth become almost 

 regularly, though shortly, bicuspid. 



The general anatomy does not offer any peculiarity requiring special 

 notice. The nervous and digestive apparatus agrees with that of other 

 ZoNiTiDiE, except perhaps that the liver is enormously largely developed. 

 The female portion of the genital system has a long sub-pedunculate recepta- 

 culum seminis, branching off at its origin. The vas deferens is very short, 

 passing into a rather widened tube, again somewhat contracted near the 

 base of the penis, which is attached by a special strong muscle. The end 

 of the penis widens very rapidly for a short distance before it joins the her- 

 maphrodite opening. I have not observed, in two specimens examined, any 

 coecal or calciferous appendages. 



