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Show 244 MESSES. COLLINGE AND GODWIN-AUSTEN ON [Mar. 19, 2. The form of the mantle-lobes indicates a relationship to some form in which the left shell-lobe has become largely developed along the whole mantle-edge together with the right, as displayed in Girasia and Macrochlamys, but in which last-named the development of the shell-lobes has been more equal and commenced at two distinct points. 3. The position and form of the caudal mucous gland. 4. The straight jaw. 5. The broad lingual ribbon and great number of teeth of a very different form. While not inclined to attach any great importance to these two last-mentioned characters, we consider them of sufficient value to place this mollusc in the subfamily Durgellince. O n comparing Damayantia smithi with Tennentia philippinensis, Semper (6), we find it differs in the presence of the coil in the amatorial organ and in the form of tbe central tooth. The separation between vagina and free-oviduct also differs. Tennentia is probably synonymous with Issel's genus. It was founded by Humbert on a species from Ceylon, viz. T. thwaitesi, which is only a synonym of Marietta dussumieri, Gray, said to be from Mahe in the Seychelles. The genus Dekhania, Godwin-Austen, type beddomei, G.-A., is also the same as Marietta and must be suppressed. Issel (4) in 1874 figured and described three species of slugs from Sarawak, one of which, dilecta, is the type of a new genus founded by him, viz. Damayantia (4. figs. 4 & 6), on external characters only. This is shown to have exactly the same peculiar concentric markings on the mantle as Damayantia smithi, and in spite of the statement of Issel that there is no shell, we believe them to belong to the same genus. These very thin membranaceous shells may easily escape notice; and, further, iu all the species from the Indian region, to which one of us (H. H. G.-A.) has devoted special attention, a shell is always present, however small and membranaceous in size and texture it may be reduced to. The two other species recorded bv Issel are D. dorice (pi. iv. figs. 7 & 8) and D. beccarii (pi. iv. figs. 9,10, & 11). The latter has a thin immature shell (fig. 10), but the jaw figured (fig. 11) has a strong central projection. Issel has placed them in the genus Parmarion. MICEOPAEMAEION, Simroth, 1893. III. MICEOPAEMAEION POLLONEEAI, n. sp. Shell (fig. 13) flat and expanded, auriculate, the apex white, shelly, the rest olive-green, membranaceous yet solid ; two whorls. Major diameter 16 millim., minor diameter 10 millim. The posterior side of the shell is very thin aud diaphanous and falls around the edge of the shell, covering the side of the visceral mass. In this respect it recalls the shell of the South Indian Africarion palleus, " Morel.," G.-A.; but here the similarity ceases, |
