XV. MATERIALS FOR A GENERIC REVISION OF THE FRESHWATER GASTROPOD MOLLUSCS OF THE INDIAN EMPIRE. Introductory Note. [Under the above title I propose, with the help of other members of the Zoo-logical Survey of India, to issue a series of short papers embodying the main taxo-nomic results of our recent survey of the freshwater molluscs of India.' The defini-tions and limitations of the genera we have adopted are in many instances different from those hitherto accepted, and it will be as well that our views should be subjected to criticism, which we will welcome, before our final monograph is published. N.A.']. No. I — The Indian Genera of Melaniinae. By N. Annandale, D.Sc, F.A.S.B., Director, Zoological Survey of India. It is convenient to separate the family Melaniidae or Tiaridae into two subfamilies, the Melaniinae (or Tiarinae) and the Paludo-minae, and to include in the former all the species with elongate narrow shells. Among the Indian forms with this type of shell only two genera have hitherto been generally recognized, namely Faunus, de Montfort and Melania, Lamarck {=Tiara, Bolten) ; but Melania has been divided into a number of subgenera, as to the names of which there has been considerable confusion. My con-clusions may be introduced conveniently by a key to the genera I now recognize. Their status and limits will be discussed thereafter. Key to the Indian Genera of Melaniidae. 1. Outer lip of shell forming a broad and prominent lobe defined above and below by well-developed canal-like prolongations of the aperture. Operculum thick, with-out spiral figure ... ... ... ... FauniiSi 2. Outer lip not lobular, upper and lower canals of the aper-ture ill-defined or absent. A. Shell very small (less than i cm. high), hairy, sculptured with spiral incised lines only. Oper-culum extremely thin, paucispiral, with the nu-cleus eccentric. Foot produced into a filamentous process behind. Marginal tooth of radula with three sharp denticulations and a pointed process near the base ... .. ••■ Mainwaringia. B. Shell large or of moderate size, as a rule without hairs, with at least a trace of longitudinal grooves and ridges. Operculum at least moder-ately thick. Foot without posterior process. 1 See Kemp and Gravely, lud. Jour. Med. Research, VII, p. 252 (1919). .-/
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