326 ^h\ 0. Thomas on new 



bread ill of the muzzle ; no percejitible external capsule over 

 the roots of the lower pair, which do not extend further bade 

 than the level of the front of the low coronoid process. Molars 

 practically as in Jlydromj/s, though larger, and the segments 

 of m^ rather more extended transversely. 



Tt/pe :— 



Limnomys asper, sp. n. 



Size that of a rather small Ilydromys. Fur crisp and 

 liarsh ; hairs of back about 8 mm. in length ; underfiir thick 

 and "NvooUy, about 6 mm. long. General colour of u))i)er 

 surface coarsely grizzled grey-brown (nearest to " iiair- 

 brown " of Ridgway), the ends of the longest hairs black, 

 those of the shorter ones dull creamy whitish ; underfiir glossy 

 whitish at base, slaty brown terminally. Lower surface dull 

 greyish wa-hed with bufFy, not sharply defined laterally. 

 Head like back. Whiskers very strong and numerous, the 

 upper ones black, the lower white. Ears short, rounded, 

 finely haired, greyish brown. Upper surface of hands and 

 feet pale brownish. Tail above and below brownish black 

 for rather more than half its length, the remainder white. 



Skull and teeth as described above. 



Dimensions of the type (taken in skin) : — 



Head and body (periiaps shrunk) 240 mm. ; tail 260; hind 

 foot (wet) 54*0 ; ear 15. 



Skull: basilar length 40*2; zygomatic breadth 2&b r, 

 nasals 15*5x6"l; interorbital breadth 11*7 j intertemporal 

 breadth 8'3 ; breadth of biain-case 21*5; breadth of muzzle 

 at centre 122; height of muzzle 11'2; palatilar length 23; 

 diastema 12*5; palatal foramina 4*4 X 2*7 ; length of m} 'i}''6. 

 Lower jaw, condyle to incisor-tip 34. 



IJab. Mount Gayata, Richardson Range, British New 

 Guinea. Alt. 2000-4000'. 



Type. Adult niale. B.M. no. 1)9. 4. 4. 1. 



This interesting rat would seem to be an early development 

 of the Ilydromys type, less modified for aquatic life than in 

 that genus, but showing many characters in common with it. 

 In its dentition, however, it is fully as specialized, having 

 only I molars, and showing no trace of the more Murine 

 type of teeth, such as may be perceived in certain other 

 members of the subfamily llydromyinge. 



