neio Jllammals from tlie Loicer Amazons. 607 



ordinary grizzled greyish, at most with a slight rufous 

 suffusion. 



I have great pleasure in naming this beautiful monkey in 

 honour of Fraulein Dr. E. Snethlage, by whose personal 

 efforts our knowledge of the mammalogy of the Lower 

 Amazons is being so rapidly increased. 



Mesomys stimulax, sp. n. 



Smaller than M. ecaudatus, and with shorter muzzle. 



General characters as in M. ecaudatus, from which I think 

 ^' Echimys ferrugineus," Giinth., cannot be separated *. Size 

 rather smaller. Colour above rather paler and more buffy, 

 but the difference is not great. Below, however, instead of 

 the whole under surface being uniformly buffy, the throat, 

 axillae, centre of chest, and inguinal region are white, while 

 the belly is more fawn-coloured. Whiskers and long hairs 

 round ears blackish. Hands and feet drabby whitish, without 

 buffy suffusion. Tail uniformly brown, thinly tufted 

 terminally. 



Skull smaller than that of M. ecaudatus, the difference 

 being almost entirely due to the considerable shortening of 

 the muzzle. Nasals shorter than in ecaudatus^ parallel-sided 

 mesially, narrowed in front, instead of being decidedly 

 broader anteriorly than posteriorly. Supraorbital edges well 

 developed. Bullns decidedly smaller than in ecaudatun, their 

 antero-internal corner not projecting angularly forwards. 



Teeth as in ecaudatus. 



Dimensions of the type (measured in flesh) : — 



Head and body 158 mm. ; tail 122 ; hind foot 29 ; 

 ear 13. 



Skull : greatest length 41 ; condylo-incisive length o6'8 ; 

 zygomatic breadth 21"6 ; nasals ll'5x4*3; interorbital 

 breadth 11*5; breadtli of brain-case 17"3; palatilar length 

 13'6 ; diastema 9 ; palatal foramina 4 ; upper molar 

 series &-Q. 



Hah. Cameta, Lower Tocantins. 



Type. Old female. B.M. no. 11.4.28.29. Original 

 number 69. Obtained 14th February, 1911, by Fraulein Dr. 

 E. Snethlage. 



The specimen had been kept some time in captivity, but 

 the differences in the skull are not such as would have been 

 affected by this circumstance. Both skull and teeth are 

 without any trace of disease. 



* Cf. Ani>. & Mag. Nat. Hist. (7) xv. p. 590 (1905), 



