130 
Likewise Scuincer'). Less exact descriptions are given by Guppet.’), 
Cravs®), and M. Weser“). 
In order to preclude incorrect representations, it is necessary to 
premise that the classification of monkeys into Catarrhini and Platyr- 
rhini is based on external distinctive features namely on the distance 
and the location of the nostrils. Catarrhini or monkeys of the Old 
World are monkeys with small distantia internarina and nostrils 
turned downward, Platyrrhini or monkeys of the New World have 
a large distantia internarina and nostrils turned sideways. 
Isiporr Grorrroy St. Hinatrw‘) takes the classification of Burron 
and of his father as point of issue for his investigations. He comes 
however to the conclusion that the distinction of monkeys according 
to their external nose, without more, does not coincide with their 
geographical dispersion over the two continents. According to him_ 
Eriodes, Lagothrix and Nyctipithecus, all of them American monkeys, 
agree, with regard to their nostrils, almost entirely with the monkeys 
of the Old World; on the other hand Semnopithecus and: especially 
Miopithecus come very near up to the monkeys of the New World. 
Is. G. Sr. Hitarre therefore proposes the following compromise: “Il 
est permis de conserver a ces caracteres toute leur généralité, a la 
condition d’en modifier l’expression, la cloison internasale étant tou- 
jours mince ou médiocrement épaisse jamais large chez les Singes 
de l’Ancien Monde, a quelque tribu qu'ils appartiennent; large ou 
médioerement épaisse, jamats mince chez les Singes américains. 
I have controlled this view by a great number of individuals. 
In my opinion it is not correct; when examining many monkeys, 
we see that the external nose of Platyrrhini with “la cloison inter- 
nasale médiocrement épaisse’ can always be distinguished from 
Catarrhini with a similar distantia internarina. It is true that it is 
difficult to express this difference in a single sentence. 
Let us first pass under review the shape of the external nose of 
typical representatives of the two groups. The different species of 
Cebus have all a large distantia internarina and nostrils turned side- 
ways; between these lies a superficial fossa internarina. The nostrils 
are rather wide oval, the oral part is the wider; from above and 
medial the processus naviculares of the maxilloturdinale penetrate 
1) H. ScuteceL, Muséum d’Histoire naturelle, p. 3 and 4, Leyden 1876. 
2) GiEBEL, Die Säugetiere, 1859, S. 1025. 
5) CuAus. Lehrbuch der Zoologie, 3 Aufl. II, S. 1199, 1876. 
4) M. Weser, Die Siiugetiere, Jena 1904, p. 771 and 776. 
6) ls. G. St. Hivarre, Extr. d'Archives du Muséum d’Hist. nat. T. 2, p. 6 and 
p. 39, Paris, 
