72 Mr. 0. Thomas on 



CrossomyK, both in strucfure and liabits, is Anotomys, fiom 

 the torrents of the high Ancles, which has altogether lost its 

 ear-conches, has equally aquatic fur and feet, but in which 

 the tail, although longer-haired below, has not such a 

 specialized swimming-fringe. 



The structural nioditications of the Beaver are of so different 

 a nature as hardly to come into the comparison. 



Crossomys Monchtoni, sp. n. 



Size considerably less than in Hydromys. Fur soft and 

 glossy, the comparatively sparse longer fur of the back about 

 IS mm. in length, the wool-fur very thick, soft, and close, 

 about 10-11 mm. in length, resembling that of Fiber. 



General colour above grey (grey no. 6), washed on the 

 back with pale yellowish olivaceous, the longer hairs with 

 black tips and isabella subterminal rings ; the wool-hairs 

 silvery white or greyish white for seven-eighths their length, 

 their tips black. Under surface silvery white, the line of 

 demarcation well-marked, high up on the sides, the hairs 

 white to their bases or very faintly greyer below the tips. 

 A narrow line down front side of arms like back, the 

 remainder white; upper surface of hands pale brown, the 

 fingers naked. Feet practically naked, the few minute hairs 

 glossy white. Tail grey throughout on the short-haired 

 part, the swimming-fringe white. 

 Skull and teeth as described above. 

 Dimensions of the type (measured in the skin) : — 

 Head and body 205 mm. ; tail 220 ; hind foot (wet) 48. 

 Skull: greatest length 40*5 ; basilar length 31*5; zygo- 

 matic breadth 22*2 ; nasals 11'4 X 5 ; interorbital breadth 5-8 ; 

 breadth of brain-case 19'7 ; height of brain-case from basion 

 12; palatilar length 17*3; diastema 10"8 ; palatine foramina 

 5 ; lengtli of upper tooth-row 5*3, of m^ 4*2. 



IJab. Serigina, Brown River, N.E. British New Guinea. 

 Altitude " not less than 4500 ft." 



Tj/jue. Adult female. B.M. no. 7. 5. 22. 3. Original number 

 36. Collected 12th October, 1906, and presented by C. A. W. 

 Monckton, Esq. 



" Iris dark brown. Caught while swimming down a 

 rapid creek."— C. A. W. M. 



Ui'omys anak, sp. n, 



A very large species with a wholly black tail, 

 ISize largest of the genus. Fur harsh; longer hairs of 

 back 28-31 mm. in length, underfur about 20 mm. Genen-al 



