J. Zool., Lond. (2004) 264, 117–124 C  2004 The Zoological Society of London Printed in the United Kingdom DOI:10.1017/S0952836904005667 A new species of bandicoot, Microperoryctes aplini, from western New Guinea Kristofer M. Helgen* and Timothy F. Flannery School of Earth and Environmental Sciences, University of Adelaide, Adelaide SA 5005, Australia, and South Australian Museum, North Terrace, Adelaide SA 5000, Australia (Accepted 16 February 2004) Abstract A distinctive new striped bandicoot of the genus Microperoryctes (M. aplini new species) is described and compared with Microperoryctes murina, another little-known bandicoot with which the new species has been confused in the past. The smallest of all living bandicoots, M. aplini is apparently restricted to high-elevation forests in the Arfak Mountains of the Vogelkop Peninsula of western New Guinea. The similarly small M. murina is known only from high-elevation forests on Gunung Sumuri, a peak in the Weyland Range of western New Guinea. The two species differ markedly in fur colour and ornamentation, pelage texture, external proportions, and quantitative and qualitative craniodental aspects, and may not be immediately related to one another. Key words: Microperoryctes, bandicoot, taxonomy, New Guinea INTRODUCTION The mouse bandicoots (genus Microperoryctes) are a group of small-bodied, ground-dwelling marsupials endemic to forested highlands in the Central Ranges of New Guinea. Most species are light brown to reddish- brown, attractively ornamented with a black dorsal stripe, and, in some species, with facial and rump stripes. One species of the genus, M. murina, differs from all others in its inornate, smoky-grey pelage, which is soft and woolly like that of many shrews and moles. This unusual bandicoot is the smallest of all described bandicoots, with a total length of < 300 mm. It is a rare species, known only by the type series of three specimens from the Weyland range of western New Guinea. Four additional specimens of another very small, striped bandicoot (in museums on four different continents) were studied, all of which originated from the Arfak Mountains of western New Guinea. Although these latter specimens have been tentatively identified in museum collections and in literature as M. murina (almost entirely on the basis of their very small size), it has been recognized for some time that they differ substantially from the type series of that species (see collective discussion by Ziegler, 1977; George & Maynes, 1990; Groves & Flannery, 1990; Menzies, 1991; Flannery, 1995; Aplin, 1998; Aplin, Pasveer & Boles, 1999; Aplin explicitly referred to the Arfak pygmy bandi- coot as ‘a potentially distinct species’). In this report the *All correspondence to: K. M. Helgen. E-mail: kristofer.helgen@adelaide.edu.au taxonomic content of the genus Microperoryctes is briefly reviewed before describing the Arfak pygmy bandicoot as a new species. MATERIALS AND METHODS Specimens discussed here are deposited in the collections of the Bernice P. Bishop Museum in Honolulu (BBM), the Museum f¨ ur Naturkunde in Berlin (ZMB), the Museum Zoologicum Bogoriensis in Cibinong, Indonesia (MZB), the Papua New Guinea National Museum and Art Gallery in Port Moresby (PNGM), the American Museum of Natural History in New York (AMNH), and the Australian Museum in Sydney (AM). External measurements were recorded by the original collectors in the field. Craniodental variables were measured by the first author with hand-held callipers to the nearest 0.01 mm (rounded here to 0.1 mm). External variables are abbreviated as follows: head and body length (HB), tail length (TV), hindfoot length (HF), ear length (E). SYSTEMATICS Order Peramelemorphia Kirsch, 1968 Family Peramelidae Gray, 1825 Subfamily Echymiperinae McKenna & Bell, 1997 Comments: Familial and subfamilial classification follows Groves (in press).