SVENSKA EXPEDITIONEN TILL MAGELLANSLÄNDERNA. BD. II. N:0 7. 163 



out of the sheath. I cannot "say however that I have seen 

 this layer so plainly that I dare to affirin that »Neomylodon 

 has had an exterior loose and pithlike bark surrounding the 

 solid central axis of the hair along its whole length. Bat 

 on a spot of the skin where the surface is cleaner than else- 

 where and which does not look as if it should have been co- 

 vered by dust or dirt, almost every hair is provided with a 

 ring or a cuff of a loose, grayish brown matter. These rings 

 are situated round the base of the hairs, close to the surface 

 of the skin. Their extension is seldom more than 1 mm., 

 usually less. They are conspicuously of epithelial origin and 

 constitute most probably the basal parts of an exterior loose 

 layer of the hair, for there does not seem to be any possi- 

 bility that it could be a portion of the epithelial hair sheath 

 which has protruded in such a manner, when the skin dried. 

 That must namely be held in position by the horny layer of 

 the epithelium and could not be attached to the hair in such 

 a manner and — tertium non datur. If this layer covered 

 the whole hair of the living animal cannot be decided, but 

 the similarity in appearance between these rings and the 

 specks mentioned al)ove show that both are of the same ori- 

 gin and that makes it probable that the hair of -»Neomyloäouy* 

 has had a more or less complete cover of a looser structure. 

 If this supposition is right the relationship between Mylodon- 

 tidce and Bradypodidce will become still closer than has 

 hitherto been regarded. When examining the hair of Neo- 

 mylodon I found once 011 the middle of each of two hairs a 

 brownish ring of a peculiar structure. They proved, how- 

 ever, to be of vegetable origin and therefore I submitted 

 them to Professor F. ß. Kjellman who kindly suggested 

 that they were formed by some green alg«, probably Prasi- 

 ola antarctica or some relative of the same. If these algte 

 have grown already on the hairs of the living animal or have 

 found the hair to be a suitable Substrate first afterwards, 

 cannot be decided. It is however worthy to be mentioned 

 for the comparison with the symbiotic algge of Bradypus. 



The next thing is to decicle if the hairs are inplanted in 

 the skin without any detinite order or if they are systema- 

 tically arranged in groups or rows. Although I have exa- 

 mined the skin on different places I cannot find that there 

 are any laws of arrangement. The hairs are scattered singly 



