qUADRUMANA. 



Some of them have the hairs on the forehead of a uniform length, 

 such as the 



Sim. appella, L. (The Sajou); and the S. capucina, L.; Buff. 

 XV, 4, 5 and 8, 9. (The Capuchin.) Both of them of dif- 

 ferent browns; in the first, the circumference of the face is 

 blackish; in the second it is whitish; but the shade of co- 

 lour in all the rest of their bodies varies between a brownish 

 black and a fawn-colour, sometimes even a white. The should- 

 ers and breast are however generally lighter, and the calotte 

 and hands darker. (1) 

 Others, again, have the hairs of the forehead so disposed as to 

 form a kind of aigrette, such as the 



Sim. fatuellus, Gm.; Buff. Supp. VII, 29. (The Horned 

 Sajou.) This animal has a tuft of black hairs on each side of 

 the forehead. (2) 



The disposition of these Monkeys is mild and gentle, their 

 motions quick and light, and they are easily tamed. Their 

 name of Weeping Monkeys is derived from their soft plaintive 

 voice. 

 In the Saimiri the tail is depressed, and almost ceases to be pre- 

 hensile; the head is very much flattened; in the interorbitar parti- 

 tion of the skeleton there is a membranous space. ' There is only 

 one know'n; the 



A\*mmscmrea, Buff. XV, 10. (The Siamiri.) Sizeof a Squir- 



(1) The Sajous and the Sais vary so much from a brown to a yellow, that were 

 there not intermediate varieties, we should be tempted to make many species of 

 them. Such is the case with tlie Sim. trepida, syricMa, luguhris, Jlavia, L. and 

 Schreb., as well as some of tliose distinguished by M. GeofFroy, Ann. du Mus. 

 XIX, 111 and 112. Spix has recently, and in our opinion improperly, multiplied 

 them still more. 



We would refer to the Sajou {Sim. apella, Lin.) the Cehus rohiistus, Pr. Max., 

 which appears to us an old one of that species. The Ceb. macrocephalus, Spix, pi. 

 1, does not seem to differ from it, so far as regards the species. We refer to the 

 Sal {S. capucina, Lin.) the Sai d gorge blanche. Buff. {S. hypolencos); the Cehus 

 libidinosus, Spix, 2; the Ceh. xanthosternus, Pr. Max., or the Ceh. xanthocephalus, 

 Spix, 3; the Ceh. cucullaius, id. 6. 



We should be more inclined to consider as distinct species, the Sajou d pieds 

 dmis, Fred. Cuv. , the Sajou hrun, id. or Ceh. unicolor, Spix, pi. 4; the Sim. Jlavia, 

 Schreber, 31, B, from which the Ceb. gracilis, Spix, pi. 5, seems to differ only in 

 the stuffing but that we require numerous observations, made on the spot which 

 these animals inhabit, before we can hope to establish their species in any other 

 than an arbitrary manner. 



(2) Here should come the Cehus cirrkifer, Geoff, and the Ceh. of the same name, 

 of Pr. Max., but which is different. Ceh. cristatus, Fred. Cuv. 



