144 



SKETCH OF THE HISTORY OF MAMMALIA. 



The Black Agouti {Dasyprocta cristaia). 



This species, to which the term crested {cristata) is 

 ill apj)lied (since the hairs of the head and neck are 

 not longer than those of the shoulders), is smaller than 

 the common species, but its general proj)ortions and form 

 are the same : it differs, however, in colour, for the hairs 

 of the back and sides, instead of being annulated with 

 various tints, as in that animal, are nearly of a uniform 

 black, whilst the long hairs of the croup are perfectly so. 

 A specimen we regarded as the black agouti, in the Paris 

 Museum, might be thus described : — black, beautifully 

 freckled with pure white, especially about the cheeks 

 and sides, each hair on those parts being once ringed 

 with white ; length twenty inches. (Fig. 92.) 



9a.— Black Agouti. 



^^'^4::^<- 



The Acouchi {Dasyprocta acuchi). 



This animal differs from the agouti in being of a much 

 smaller size, lighter make, and deeper colour, and espe- 

 cially in having a much longer tail, this appendage mea- 

 suring two inches : it is very slender, being not much 

 thicker than a crow-quill, and covered with short scattered 



