1, MYCETEs. 39 
fur, when it is bent back and examined, as to make one almost 
doubt if the black specimens are not another state or local variety 
of the red ones.— Ann. and Mag. N. H. 1845, xvi. p. 217. 
M. I. Geoffroy states there can be no doubt that M. niger and M. 
stramineus of Geoffroy are the same species, M. niger being the males, 
and M, stramineus the females and young. There are in the Jardin 
des Plantes young males changing into the black state. Stentor 
Sflavicaudatus, Geoff., is a variety, and S. fuscus, Geoff., a pale speci- 
men of Mycetes ursinus. (See Cat. Mus. Paris, p. 53.) 
Slack observes, “Dr. Gray lays great stress upon the texture of the 
hairs as a specific distinction. In AL. seniculus the hairs of the adult 
are soft to the touch, while those of the young are hard and rigid.” 
—Journ. Acad. N. S. Phil. 1862, p. 516. 
The species may be divided thus :— 
1. Forehead high, with the hair reflexed, forming a ridge across 
the centre of the crown. 
a. The fur rather rigid in 1, 2, 3. 
b. Fur soft, silky, elongate, 4, 5. 
2. Forehead with the hair directed forward ; crown smooth, with 
radiating hairs. 
a. Fur short, rather rigid in 6, 7, 8. 
6, Fur rather soft, 9. 
¢e. Fur very long, silky, 10. 
1. Mycetes ursinus. The Araguato. B.M. 
Brown or blackish, yellow-washed; hairs rather rigid, brown, 
with yellowish tips. Male, female, and junior. 
Mycetes ursinus, Desm. Mamm.; Pr. Max. Abbild. t.; Gray, Ann. § 
Mag. N. H. 1845, xvi. p. 218. Stentor flavicaudatus, Geof. Simia 
ursina, Humb, 8. guariba, Humb. Mycetes fuscus, Kuhl; Spiz, 
Bras, t. 80. 
Var. Yellow; the tail, head, feet, sides of the head, body, and 
limbs yellow. Male. B.M. 
M. stramineus, Sper, Bras. t. 31. M. barbatus, foem., Spix, Bras. 
t. 33. 
Hab. Brazil. 
2. Mycetes seniculus. The Golden Howler. B.M. 
Reddish chestnut; middle of the back golden yellow; hair one- 
coloured to the base, short, rather rigid, without any underfur ; 
hair of the head short. Males and females. 
Alouate, Buff. H. N. xv. p. 5; Suppl. vii. t. 15. Simiaseniculus, Linn. 
S. N.i. p.87; Gray, Ann. & Mag. N. H. 1845, xvi. p. 219. My- 
cetes seniculus, Kuhl. Royal Monkey, Penn, 
Hab. Brazil; Guiana. In Bolivia a paler variety. 
