160 PHALANGERIDiE. 



millixn. 



Hind foot 26 



.Ear 19 



SkuU, see p. 162. 



Hah. Victoria (Bass Eiver). 

 Type in the Melbourne Museum. 



6. PETAUEUS, 



Type. 



Petaurus, Shaw, Nat. Misc. ii. text to pi. Ix. (1791) . . P. australis. 



Ptilotus, G. Fisoh. Zooqn. iii. p. 512 (1814) P. australis. 



Beiideus, Waterh. P. Z. 8. 1888, p. 151 P. soiureus. 



Xenochirus, Glog. Handb. Naturg. p. 85 (1842) P. sciureus. 



Size medium or small. Pur unusually soft and silky. Ears 

 fairly large, oval, nearly naked, not tufted. Flanks with a broad 

 flying-membrane, stretching from the outside of the fifth fore finger 

 (PL XV. fig. 11) to the ankle, where it is inserted just over the 

 large internal malleolas of the tibia. Fore toes evenly lengthened 

 towards the outside, the fifth (which bears the membrane) the 

 longest, at least in the larger species, the others following in the 

 regular order 4, 3, 2, 1 ; in the smaller species, however, the order 

 is 4, 5, 3, 2, 1. Claws very strong and sharp, much curved. Tail 

 long, not distichous, evenly bushy all round to its extreme tip. 

 Special glands, no doubt sexual in their nature, present both on the 

 crown between the ears and on the chest; more prominent and 

 better developed in males than in females. 



Shull short, broad, and strongly buUt. Nasals widely expanded 

 behind. Supraorbital edges with sharp overhanging ridges. 

 Posterior, squamosal portion of zygomata much inflated by air-cells. 

 Palate nearly or quite complete ; a small pair of vacuities opposite 

 m.' generally present. Bullse inflated, variable in size. Lower jaw 

 with a small but distinct communication between the masseteric 

 fossa and the inferior dental canal. 



Denmon-.-l. 1^, G.\, ^.'f^^w ^- Mfl7l= 16+^x2 

 = 40. 



Upper i.' very large, exceeding the canine in length. Premolars 

 simple, pointed, two-rooted ; p.^ nearly as large as p.* ; p.' 

 much smaller, but not minute. Molars squarely rounded, quadri- 

 ouspid, except the last, which is triangular. Lower minute teeth 

 generally four in number, consisting apparently of i.", p.', p.', 

 and p.^, nearly or quite touching one another ; aU present in 

 most specimens ; an additional one (probably i.') occasionally deve- 

 loped. 



Bange. Papuan and Australian subregions, from Gilolo to 

 Victoria. 



