Callithrix personata, amicta, C. cuprea, C. melanochir.
One species C. sciurea, or saimiri, ought to be separated from the rest WAGNER makes of it the genus Clayacthric. Its tail is not prehensile, but depressed, and often twisted round objects. Its head is flat ; between the two orbits there is but a membranous septum, instead of a bony wall, and the glans penis is round, as in man ; while it is flat, in the form of the head of a mushroom, in the Cebi, which have the penis in continual erection.
Sirth Genus. Nochthora F. Cuviza.
Aotus HUMBOLDT. Dourocouli.
Differs only from the genus CaMaris. by large nyctalope eyes and ears, which are partly co vered by the skin, and by a small face. The species of this genus have nocturnal habits, and a feline physiognomy, They feed not upon fruit, as the precedent species, but on small birds and insects. In their form, noc turnal habits, and great sensibility to light, the Arochthorce approach very much to the species of the genus Ste22ops, from which they differ in their internal structure. Their nails are straight, long, and sulcated. The dental 4 . 1-1 anformula is: incisors - c Ines—, molars 4' 1-1 6-6 They inhabit Brazil.
o—f.) Spec. — Nochtkora trivirgata.
7. Seventh Genus. Pithecia. Saki.
The characters of this genus consist in the bushy, but short, prehensile, and long tail, the slender body, the large ears, the dense beard in some species, and the straight, but claw-like nails. Their incisor teeth are more prominent than in the genus Cebus. Brazil.
Spec.— Pithecia Satanas, P. rufiventris, P. kucocephala, P. inusta.
8. Eit„Ihtli Genus. Hapale. Ouistiti, Sahui.
This genus departs more from the typical genera of monkeys of the New World than any other, inasmuch as they have only the same number of teeth as the monkeys of' the Old 4 1-1 World,viz.32: incisors 4, canines molars
5-5 The nails, by being compressed and pointed, assume the appearance of claws, ex cept the thumbs of the after-hands, which have flat nails; but the thtunbs of the fore-hands, which have no flat nails, are so slightly. sepa rated from the other fingers, that it is not without hesitation that the Ouistitis are called four-handed or Quadrumana. All the species belonging to this genus live in troops.m the Brazilian forests, where they spnng from bough to bough, more like birds than quadru peds. They resemble squirrel.s, whose form they seem to represent in South America, which possesses but one species of squirrels, Sciurus cestuans. Their incisors, canini, and false molars, are sharp and acuminated. The inferior incisor teeth are long, narrow, and prominent. They feed upon insects, eggs,birds. Their voice is a gentle whistle, which de Humboldt* compares to the voice of some birds. He says that their larynx is similar to the inferior larynx of birds, but he did not illu.strate this opinion by sufficient anatomical details.
The species can be divided into two groups. The first contains those in which the infenor incisors are cylindrical and the tail is annular.
Hapale jacchus, H. penicillatus, H. leuco cephalus.
In the second, the inferior incisors are truncated like the mouthpiece of a pipe, and the tail is not annular.
H. argentatus, H. ?Ili& s, H. ursulus, H. labiatus. chrysomelas, H. rosalia, H. chrysopygus, H. aylipus.