10 ARKIV FÖR ZOOLOGI. BAND 12. N:0 10. 



From tliis description is apparent that the old male 

 shows more or less white on several places, especially the 

 face, the ears and the feet, where no such markings occur 

 in the young female. It might be possible that this white 

 ought to be regarded as a sign of great age, or even senility, 

 and thus no specifie characteristic. Nothing can be said 

 about this with full certainty until more material is exam- 

 ined. The fact is, however, in any case noteworthy. On 

 the other hand such markings as occur both in the young 

 and in the old animals, as the white upper lip and the white 

 stripe on the back of the ham from the root of the tail and 

 downwards, must be regarded as characteristics apt to dis- 

 tinguish the red broeket of the Chaco Austral from the one 

 from the Chaco Central in which latter they are lacking. 

 As these markings appear to be of a common occurrence 

 among the red broekets, their absence from the one living 

 in the Chaco Central speaks for the racial distinction of the 

 same as well. 



The hoofs of the hind legs measure along the upper 

 ridge 35 mm. in length, and the breadth of the outer or 

 upper surface from the upper ridge to the outer lower margin 

 is 22 mm. 



Mazania simplicicoriiis argeiitiiia n. subsp. 



1 J", from the Argentine Chaco, presented by Captain 

 A. Ros to the Zootomical Institute of the Stockholm High 

 school.i 



2 5 signed: »Gama. Guazu uirä. Ind. Cahitä. Chaco 

 Central Rio de Oro Junio 1896. A. Ros.» This latter spe- 

 cimen belongs to the R. Nat. Hist. Mus. 



Both are fully adult, but the premolars very little worn ; a 

 small canine is present on the right side of the maxillar^' of 

 the male. 



ef $ 



Greatest length 185 mm. — 



Occipito-nasal length 161 » — 



^ Professor W. Leche has kindly permitted me to examine this skull 

 which he received from Captain Ros together with some other specimens 

 collected in the Chaco Austral. The exact locality of this skull is not 

 recorded. 



