184 Mr. 0. Thomas on Mammals from 



XVIII. — Mammals from the River Siipinaam, Demerara, pre- 

 sented hy Mr. F. V. McConnell to the British Museum. 

 By Oldfield Thomas. 



(Published by permission of the Trustees of the British Museum.) 



Mr. F. V. McConnell, the donor of the valuable collection 

 from the Kanuku Mountains, of which I gave an account in 

 1901 *, has since presented to the l^ational Museum a 

 number of smaller collections from other parts of British 

 Guiana. The latest of these is from the River Supinaam, a 

 tributary of the Lower Essequibo, and is of sufficient import- 

 ance to make a list of the species contained in it worthy of 

 publication. 



1 . Cebus apiculatuSj Spix. 

 Two specimens. 



One. 

 One. 



2. Pithecia pithecia, L. 

 3. Pithecia chiropotes, Humb. 



4. Tonaiia Icephotis, sp. n. 



One. 



Allied to T. sylvicola, d^Orb,, which would appear to be 

 distinguishable from T. amhlyotis by its larger size, and 

 notably its larger skull. General characters as in the former 

 species, but ears markedly larger, measuring (after damping) 

 30 mm. in length from the inner base by 22'5 in breadth, as 

 compared with 25x21 in an example similarly treated of 

 T. sylvicola. Feet smaller than in sylvicola^ the distance 

 from behind the base of the calcar to the ends of the claws 

 18 mm. as compared wntli 20-21 in sylvicola. 



Colour quite as in T'. sylvicola, though the grey collar 

 hardly goes up so far on the sides of the neck. 



Skull as in T. sylvicola, the posterior palate rather nar- 

 rower. 



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



Forearm 56 mm. 



Ear (wet) 30 x 22'5 ; third finger, metacarpus 45, first 



♦ Ann. & Mag. Nat. Hist. (7) riii. p. 139. 



