248 Mr. R. I. Pocock on 
that of late years two genera only have been admitted— 
namely, Hapale, which has abnormal lower incisor teeth, and 
Leontocebus or Midas, in which these teeth are normal. 
In 1912, however, Elliot (‘A Review of the Primates,’ i. 
pp: 179-233) grouped the species as follows :— 
1. Genus Seniocebus, Gray, for bicolor (type), martins:, 
meticulosus. 
2. Genus Cercopithecus, Gronov., for midas (type), ursulus, 
rufimanus. 
3. Genus Leontocebus, Wagn. (type, chrysomelas). 
Subgen. a. Marikina, Reich., for chrysomelas, rosalia, 
“leonina, 
Subgen. b. Tamarinus, Trt., for labiatus, mystaz, 
devillei, illigert, imperator, apiculatus, pileatus, 
etc. 
4, Genus Gidipomidas, Reich., for wdipus (type), geoffroyi. 
5. Genus Callithriz, Erxl. , for jacchus, penicillata, argen- 
tata, leucopus, aurita, pygmea, and many others 
usually referred to the genus Hapale. 
With a few modifications in the arrangement of the species 
and in nomenclature, this classification is a compromise 
between Gray’s, published in. 1870, and Trouessart’s, pub- 
lished in 1899. In the matter of nomenclature, the chief 
points to notice are the use of Cercopithecus, Gronov., for 
midas, of Callithrix for jacchus, and the selection of chryso- 
melas as the type of Leontocebus. The characters used for 
differentiating the genera and subgenera are those supplied 
principally by the degree of hairiness of the face, head, and 
neck ; but no characters are cited for distinguishing Senio- 
cebus from Gidipomidas* or Cercopithecus from Leontocebus. ’ 
Hence it may be inferred that the genera, as defined, have no 
secure basis, and it cannot be admitted that the classification 
* In spite of one’s personal liking and respect for Dr. Elliot, it is 
necessary to explain as a warning to the unwar y that he was quite unequal 
to the task of monographing the Primates, or of making even a present- 
able attempt at it. That he had no real acquaintance with the genera 
and species of the order is shown in the present instance by his describing 
the very well-known Pinché marmozet (Gdipomidas wdipus, Linn.) as a 
new species named Seniocebus meticulosus—that is to say, he diagnosed 
the same species under two different names and referred it to two distinct 
genera within a few pages of his monograph. Moreover, the figure of 
the skull he published to illustrate the dental characters of Callithrix 
(Hapale) contradicts the generic diagnosis—which, by the way, is itself 
wrong,—because the species leucopus is not a Callithriv at all, but, 
according to Elliot’s system, should have been referred to Seniocebus or 
Cer copithecus or Leontocebus, I know not which. 
