378 Lieut.-Col. Godwin-Austen on Durgella Christiane. 
one from life ; for from the spirit-specimen it would appear to 
be of a very fine dark colour, contrasting remarkably with 
very much paler-coloured shell-lobes. 
The species was first described (on shell-character alone), 
under the title Vitrina Christiane, by Mr. W. Theobald, in 
J. A. S. B. 1864, p. 245; but he had apparently never seen 
the animal. In his ‘Catelogue of the Land and Freshwater 
Shells of India,’ published in 1876, it is placed in Section C 
of the genus Helicarion. The five sections into which this 
genus is divided are quite artificial, and apparently based on 
shell-characters, which in these slug-like forms are of no 
value whatever. For instance, H. Bensoni, to which Chris- 
tvane is compared in the original description, is closely 
allied to Macrochlamys. 
Shell (original description). Testa subglobosa, tenuis, polita, dia- 
phana, nitida, supra costulate striata, infra planior, colore 
succineo ; apice pallido, vix elevatiusculo ; peripheria rotundata ; 
apertura parum obliqua; anfractibus 34, lente crescentibus. 
Long. 13, lat. 11, alt. 8 millim. 
Habitat in insulis Andamanicis. 
It is figured in ‘ Conchologia Indica,’ pl. lxvi. figs. 7-10. 
Descr. Animal from spirit-specimen about 14 inch long 
when fully extended. Whole body very dark (probably indigo- 
grey), with the shell-lobes conspicuously pale-coloured. Ap- 
parently long, and foot narrow, with a distinct central area and 
lateral pallial line. ‘The vight neck-lobe is small, dark-coloured, 
of triangular form, the left neck-lobe commencing as a very 
narrow strip at the respiratory orifice, and widening gradually, 
but to no great extent, towards the left side. The right 
shell-lobe is largely developed even as contracted in the spirit, 
and in life must extend over all the right and posterior side 
of the shell. ‘The left shell-lobe is given off from the edge of 
the mantle on the left anterior margin, and is broadly tongue- 
shaped, in length about four times its breadth, and must also 
cover a very large surface of shell when fully extended. The 
extremity of the foot is square, with a mucous gland overhung 
by a large lobe. ,The generative orifice is just behind and a 
little below the right eye-tentacle. The generative organs 
are the same as in Durgella assamica*, there being no ama- 
torial organ. ‘The spermatheca is long and small, expanding 
at the end into a large pear-shaped sac. The albumen-gland 
is large and granular; but I failed to trace out the herma~ 
phrodite duct and ovo-testes. 
Odontophore. The buccal mass is large and broad, with a 
* Vide Linn. Soc. Journ, Zool. vol. xy. pl. xxi. fig. 2, &e. 
