Arrangement of the Marmosets. 19% 
their earlier division simply into two by the characters of the 
teeth having been rejected by Elliot *, whose arrangement in 
turn has been modified by Pocock fT. 
Elliot recognizes five genera, as follows :— 
Sentocebus, with type bicolor. 
Cercopithecus, type midas. 
Leontocebus (type chrysomelas), with two subgenera, 
Tamarinus (type mystav), and Marikina (type 
chrysomelas). 
Gidipomidas, type wdipus. 
Callithrix, type jacchus. 
Pocock modifies this, largely on the characters of the ears 
and feet, to the extent of rejecting Seniocebus, which he unites 
under the name of Mystax with Cercopithecus and_ the 
“ Tamarinus” subgenus of ‘ Leontocebus,” recognizing Leon- 
tocebus as a full genus, and, of course, also recognizing Calli- 
thriv, which he rightly, for the time being, calls Hapale. 
His four genera are thus :— 
Leontocebus, type chrysomelas. 
Gidipomidas, type wdipus. 
Mystax, type mystax. 
Hapale, type jacchus. 
But it appears to me that in this scheme there is no very 
satisfactory place for the Sentocebus section (type bicolor), 
for while the general appearance and short-haired or naked 
face of its members show relationship to the short-eared 
CGidipomidas, their ears are as long as in Mystax. To get 
out of this difficulty I would suggest that we should recognize 
Seniocebus, with which, besides the naked-faced bicolor, 
martinsi, and meticulosus, we might place leucopus, with face 
short-haired, though not talked: 
It is noteworthy that all the groups, used here for con- 
venience’ sake as genera, can be readily distinguished by the 
coloration of the tail and limbs, in spite of the ‘wide variation 
in the colours of the body and head. On this basis, and with 
the difference in the presence or absence of ear-tufts, I would 
* ‘Primates,’ i. pp. 179-238 (1912). 
+ “The Genera of Hapalide,” Ann, & Mag. Nat, Hist. (8) xx. p. 247 
(1917). 
