307 A REVIEW OF THE MARSUPIAL GENUS SMINTH0PSI8 (PHASCOGALINAE) AND DIAGNOSES OP NEW FORMS. By Ellis Troughton. (Seven Text-figures.) [Read 30th September, 1964.] Introduction. In his arrangement of the Genus Sminthopsis in the British Museum Catalogue of the Marsupialia (1888) Oldfield Thomas was limited to such sparse and inadequately-localized material that this mouse-like group of terrestrial marsupials, with the descrip-tion of additional species, has become involved in hopeless confusion. Referring to the unusually negative diagnostic features of the genus, Thomas, in a footnote to his "Synopsis of Species", stated that "Owing to the close resemblance existing between the skulls and teeth of the different species of Sminthopsis It has been found impossible to make this synopsis very definite in its details, but it is nevertheless thought useful to draw attention to such characters as, by reference to the fuller descriptions, will assist in the identification of specimens". Lack of specific series also rendered his diagnoses of the physical characteristics far too general on such specific criteria as the sole-pad pattern, and the presence or absence of smooth or minutely striated apical areas. The comparative length and degree of incrassation of the tail also proves to be variable in individuals of several species, according to seasonal and environmental conditions. Such variation, combined with the general lack of distinctive coloration, has created the impression that specific differentia-tion is often impossible. As a result, specific relationships have been hopelessly confused, and a preposterous distribution attributed to several of the species. The diagnostic pattern of the pads at the base of the toes may briefly be defined as: (a) In crassicaudata fine overall granulations, the subspecies centralis with an enlarged row of granules down the centre of each pad; (&) In murina/leucopus a longitudinal apical row of enlarged granules which, with wearing down, may appear as faintly serrated apical pads; (c) In lumlioltzi the well-defined oblong-ovate apical areas have microscopic transverse striae, not conceivably due to granular wearing down; (d) In larapinta there is a small smoothly rounded apical area set amongst the relatively minute granules, as distinct from the enlarged apical "bead" on the pads of macrura. Two notable exceptions, Sm. hirtipes and longicaudatus, have the soles as ■subsequently described and figured. Confusion regarding these sole-pad patterns has resulted mainly from a general neglect of the elementary collecting method never to skin the first specimen of any small mammal from each location, and then alternatively to skin and preserve specimens of a series in spirits. Not only are the sole-pads distorted by drying, but pinning-down through the apical pads obliterates their pattern. The feet should invariably be held down by pins crossed at the middle, preferably with the soles upward to avoid flattening the pads. The speciflc importance of the sole pattern in a genus so lacking in distinctive coloration and cranial characters is indicated by the following summary. In his description of murina in the Catalogue, Thomas recognized a variation in the sole-pads (due to wear in this species) when stating that the finely granulated projections at the base of the toes were without "distinct transversely striated pads, although on their summits several of the granulations sometimes coalesce and form small irregular and smooth pads". This observation anticipated the eventual subspecific merging by Tate (1947) of leucopus of Tasmania and f^rruginifrons (N.S.W.) with Proceedings op the Linnean Society of New South Wales, 1964, Vol. Ixxxix, Part 3.