the Lower Amazons. 269 



7. Aotus trivirgatus, Humb. 

 <$ . 64; ?. 66,67. Manacapurii, Rio Solimoes. 



8. Hapale emilio?, sp. n. 



(J . 36 ; ? . 37. Maloca, Upper Curua' River, Upper Rio 

 Iriri, R. Xingii*. 



Near H. melanurus, but with white muzzle and no light 

 hip-stripe. General coloration somewhat as in melanurus, 

 the shoulders and fore-back silvery grey darkening to rather 

 browner grey on the rump. Hairs of under surface silvery 

 grey. Crown between ears black or blackish, the muzzle in 

 front of the black quite white ; cheeks white; chin white, 

 practically naked. Ears large, without tufts, their thin 

 scattered hairs brown. Arms grey, whiter on their inner 

 aspect, hands blackish brown. Legs grey on outer, whiter on 

 inner side, but both aspects more or less suffused with buffy. 

 Feet blackish. Tail black except for its basal inch, which 

 is brownish grey. 



"Eyes yellowish brown. Face pink. Ears black at their 

 edges."— E. S. 



Dimensions of the type (measured in flesh) : — 

 Head and body 199 mm. ; tail 308; hind foot 61; 

 ear 29. 



Skull : greatest length 44 ; condylo-basal length 35 ; 

 zygomatic breadth 29 ; breadth across orbits 25*5 ; maxillary 

 tooth-row 11*5. 

 Hab. as above. 



Type. Adult female. B.M. no. 20. 7. 14. 12. Original 

 number 37. Collected 10th November, 1914, by Fraulein 

 E. Snethlage. 



This little marmoset, to which Fraulein Snethlage has 

 drawn my special attention, and which 1 am pleased to name 

 after her, is a member of the H. argentatus group, but is 

 readily distinguishable by its white muzzle and the absence 

 of a light hip-stripe from H. melanurus, the only species it at 

 all resembles. Of the other species of the group, H. argen- 

 tatus is almost quite white, apart from its black tail, and has 

 no blackish on the head. H. chrysoleucos has hairy ears and 

 a pale yellowish tail. — H. melanoleucos } Ribeiro, the Para 

 co-type of which is now in the British Museum, is wholly 



* The Curua River is marked in Stieler as a tributary of the main 

 Amazon, with its outlet near Santarem ; but I prefer to accept Fraulein 

 Snethlage's statement that it is an affluent of the Iriri. 



