1871.] DR. J. E. GRAY ON THE BRADYPODIDjE. 429 



Mr. Janson, junior, both inquired of me if I knew any green species 

 of Sloth, for that was the colour of the living species in Nicaragua. 

 There seems a tendency, according to the examination of the dried 

 skins, in several of the species to be more or less tinted with this very 

 unusual colour among Mammalia ; and the colour seems to fade in the 

 preserved skin ; for the skin of the three-toed Sloth, which Dr. See- 

 mann brought with him and said was quite green when alive, is only 

 green on the sides, which have been covered by the arms and conse- 

 quently less exposed than the other parts of the body. In one of the 

 specimens of the Unan or two-toed Sloth, the long hair of the back 

 of the head is whitish, and more or less dark green in a great part 

 of its length, looking as if it had been all bright dark-green when it 

 was alive. 



Unfortunately a few only of the specimens in the Museum, those 

 more lately received, have their special habitat. The rest were re- 

 ceived from the Zoological Society or the Haslar Hospital, or have 

 been purchased of dealers, and have only had the habitat of South 

 America attached to them. 



I have received the following interesting letter from Dr. Seemann : — 



" Dear Sir, — The Sloth (Jrctopithecus) I brought home was 

 caught in the woods surrounding the Javali gold-mine in the Chon- 

 tales district of Nicaragua, about 2000 feet above the sea-level, a 

 country having nine months of rain during the year. The natives 

 call this animal ' Camaleon,' and say that it is very rare, which 

 may be the case, as during all my travels in the country I have 

 never met with it before. But, on the other hand, it should be borne 

 in mind that it has almost exactly the same greyish-green colour as 

 Tillandsia usneoides, the so-called 'vegetable horsehair' common in 

 the district ; and if it could be shown that it frequented trees covered 

 with that plant (a point I hope to ascertain during my next visit in 

 June next), there would be a curious case of mimicry between this 

 Sloth's hair and the Tillandsia, and a good reason why so few of 

 these Sloths are seen. When the animal first came into my pos- 

 session it was much greener than its preserved skin is now, which 

 has been dried over the fire, and it remains to be seen whether the 

 greenness is owing, at least in part, to the fact that the hair becomes 

 covered with minute cryptogamic organisms, the damp climate and 

 thick gloomy forests being favourable to their growth. I had no 

 microscope with me to clear up this point ; but this you will, of 

 course, easity ascertain. I had the animal alive for about a month, 

 feeding it on the young leaves of Cecropia peltata, an urticaceous 

 fast-growing tree of the district ; and it used to eat most during the 

 night, when it was also most lively. One night it escaped from its 

 prison, and next morning was found about 800 yards off, in a water- 

 but, whither it had to make its way over a cleared hill, where there 

 were no shrubs nor trees, which rather puzzled me. During my 

 temporary absence from Javali the servants neglected to feed it, or 

 else I had hoped to bring it to London, to present it to Dr. Sclater. 

 It had great strength ; and in order to pull it away from the tree 

 to which it was holding, your hands were necessary. On those 



