a new Genus of Opossum. 137 



of tlie family, Uiat a distinct genus should apparently be 

 formed for its reception. 



From its far southern habitnt this might be called 



NOTUDELPHYS, gen. nov. 



Allied to Marmosn^ but of a more predaceous type, the 

 modifications of tlie skull being- all those associated with 

 greater biting-power. 



External characters about as in Marmosa (sui)genus 

 Thylamys). Feet proportionally more bulky. Ears and tail 

 comparatively short, the latter incrassated. 



Skull -with shortened muzzle and widely spread zygomatic 

 arches. The siiortening of the muzzle, as compared with 

 Marmosa^ is closely parallel to that in Dasyurus as compared 

 with PhasGogale, occurring in the premolar region, and being 

 obviously for the increase of the biting-power. Nasals 

 expanded in their posterior third, the hinder extension not 

 of great length. Interorbital region short, its edges quite 

 without ridges, though there is just an indication of post- 

 orbital knobs. Brain-case smooth, the lambdoid ridges very 

 small. Palate imperfect opposite the first three molariform 

 teeth. Bullae of medium size. Lower jaw strongly bowed 

 below, the front edge of the coronoid nearly vertical. 



Upper incisors as in Marmosa, the first pair not longer 

 than the others. Canines remarkably long, slender, little 

 curved. Premolarifortn teeth evenly increasing backwards, 

 but all small in proportion to the size of the skull, and set 

 closely together, their combined length barely exceeding that 

 of two of the larger mohirs, while in Marmosa and other 

 opossums the length of the three anterior premolars approxi- 

 mately equals that of three of the molariform teeth. Molars 

 proportionally large and heavy, their breadth about half that 

 of tlie palatal space between them. 



Lower incisors small, closely set, the two median ones 

 touching each other, and the outer ones pressed for their 

 wjiole length against the canines behind them. Canines 

 long, nearly veitical, much less proclivous than in Marmosa. 

 Molariform teeth h\rge, their anterior outer cingulum unusu- 

 ally strongly deveh)[)ed. 



Genotype : — 



Notodelphys halli\ sp. n. 



General ap])earance not unlike that of Marmosa elegans. 

 Fur not very long, but fine and close. General colour very 

 much as in grey examples of M. eleyans, with a dark grey 



