ÖNNBERG, ON SOME MAMMALS FROM THE ARGENTINE CHACO. 7 



is, in addition to its size, the thickness of the pedicels and 

 the short and thick, biit forked antiers. This forked state 

 of the antiers gives a superficial likeness to Hippocamelus, 

 but otherwise the skull of the latter is very different with 

 its deep and triangulär preorbital pit, while the same of this 

 Mazama is roundish and rather shallow. A further examina- 

 tion of the antiers of this brooket proves also that they are 

 not regularily forked, because the additional point is on the 

 left antler situated in front of, but on the right one on the 

 back of the main spike. This fact makes it uncertain whether 

 the males of this broeket always, when they have reacbed 

 full maturity, grow this kind of forked antiers, or not. If 

 they do, they deserve, of course, full specific rank, and there 

 is one thing which rather strongly speaks for the probability 

 of this, and that is the unusual thickness of the pedicels. 

 They would not have needed to grow to such dimensions, if 

 they only had to carry a simple spike. The great length of 

 the preorbital portion of the skall is also an interesting 

 feature and its relation to the condylobasal length of the 

 skull resembles the same of the large red broeket described 

 by Allén from Brit. Guiana under the name of Mazama 

 americana tumatumari, but supercedes the same of all other 

 broekets. 



The size of the teeth is also very large in this new 

 broeket, but to f ully appreciate this, it must be pointed out 

 that the molars of the typical male specimen already are 

 so strongly worn that the length of the upper molar series 

 bas become secondarily reduced in size. This is made clear 

 by a comparison with the young female in which the com- 

 bined length of the not worn m^ and m^ amounts to 25 mm., 

 while the same measurement of the old male has become 

 reduced to 22 mm. It can be concluded from this that the 

 molar series of this new broeket, before it is too much worn, 

 is very much larger than in the typical M. rufa. 



The difference with regard to other cranial dimensions 

 is elucidated by the table of measurements above. 



The female specimen, which still has its milk premolars, 

 has also small canines in the upper jaw. 



The hair on the upper side of the neck is reversed in 

 both specimens. 



