198 MR. OLDFIELD THOMAS OX XEW [Nov. 3, 



Fhalanger cannelikf, Pseudochirus corinnce, Dasyurus alhopunc- 

 tatus, and Leptomys elegans, the last two having been previously 

 unrepresented in the National Museum. 



The new forms were described as follows : — 



Hyomys, g. n. (Muridse). 



Size very large ; form bulky. Fvir coarse and harsh. Feet 

 proportionally shoi't ; pollex with a broad nail. Tail of medium 

 length, very coarsely scaled, practically naked. Mammae — 2 = 4. 



Skull stout and heavily built. Nasals very broad in front, 

 narrowing rapidly behind to a point. Postorbital processes 

 present, quite separate from the supraorbital ridges, which, 

 though distinct, are not heavily developed. PaJatal foramina 

 short ; posterior palate cut out to level of front of m.'^ Bullae 

 small, little inflated, each with a raised rim running along its 

 inner margin. Paroccipital processes strongly developed. 



Incisors large, equally broad above and below, and of normal 

 depth. Molars (see PI. XXIII. figs. 2 a & 2 c) very large and heavy, 

 their length one quarter the basilar length, and their bi'eadth 

 nearly equal to that of the palate between them ; very distinctly 

 laminate, though the laminae have got the normal murine cur- 

 vature. M.^ and m.^ each with a well-developed antero-internal 

 cusp so joined with the anterior lamina as to form a distinct 

 Y-shaped structure when worn ; no antero-external secondary 

 cusps. M.^ with the posterior overhang very unusvially developed. 

 Two anterior lower molars with the normal posterior supple- 

 mentary cusp very large, so as to form a short extra lamina 

 extending from the centre of the tooth to its inner edge. 



Type, Hyomys 'meeki. 



This genus was not distinguished by any single character of 

 marked importance, but the gigantic Rat on which it was based 

 could not be referred to any of the known Papuan genera of 

 Muridse. Its molars, while enormously larger, had the general 

 appeai^ance of those of Mus or Uromys, and had nothing of what 

 might be called the zigzag character exhibited in Crateromys, 

 Lenomys, and Mallomys, to none of which did it seem specially 

 allied. 



Hyomys meeki, sp. n. (Plate XXIII. figs. 2 a-2 c.) 

 Fur harsh, general body-hairs about 25 mm. in length, but 

 a number of bristles 60 to 70 mm. long intermixed with the 

 shorter fur. General colour dark slaty greyish, the hairs grey 

 proximally, with black or brown ends ; longer bristles dark with 

 whitish or buffy ends. Under surface dirty greyish, not sharply 

 defined, the bases grey, the ends dirty buflfy. Head like 

 back; whiskers very numerous, stifi", black. Ears short, rounded, 

 naked ; a small tuft of whitish hairs above their anterior base. 

 Limbs uniformly brown throughout ; upper surface of hands and 

 feet nearly naked, blackish ; palms and soles naked, pads broad 

 and fleshy ; fifth hind toe reaching to the end of the first phalanx 



