234 ALLEN'S NATURALIST'S LIBRARY. 



marest from the same specimen in Paris, which Kuhl described 

 under the name of A. geojfroyi. Every gradation is to be met 

 with between this and the form described by Dr. Gray as A. 

 ornatus, in which the face is entirely black, the whiskers pale 

 reddish-yellow, the patch of erect black hair on the forehead 

 yellowish at its base ; the top of the head, sides, lower back, 

 rump, upper part of the arms, outer, inner and posterior por- 

 tion of the thighs and legs, and under side of the base of the tail, 

 brownish-red; nape, shoulders and remainder of the tail red- 

 dish-brown, washed with black; lower part of arms, fore-arms, 

 hands, feet, and anterior aspect of thighs and legs, black. 



In some specimens the grey, or reddish-black colour, merges 

 on the under surface, into yellowish-cream, or rufous, and the 

 black wash is more or less distributed. 



Mr. Alston, in speaking of this species, remarks that the 

 best character by which the darker (A. ornatus) forms may be 

 distinguished from our next species (A. rufiventris) is the want 

 of a distinct line of demarcation between the colours of the 

 upper and lower parts, the tint of the flanks, whatever it may 

 be, passing almost insensibly into that of the breast and belly 

 in all the varieties. 



Distribution. The variation in colour described above is not 

 due to local causes, every variety occurring between the lightest 

 and darkest, in all the regions which this species is known to 

 inhabit. The localities from which it has been recorded are 

 on both the Atlantic and Pacific coasts of Nicaragua ; Costa 

 Rica, where it occurs in large numbers from the coast forests 

 up to nearly 7,000 feet on the mountains ; Panama, and the 

 U.S. of Colombia. 



Habits. Geoffrey's Spider-Monkey is gregarious and arboreal, 



