460 DR. E. A. GOELBI ON THE [Julie 5, 



markings are on the limit between distinct and indistinct, and I 

 consider this circumstance as a good external character for a rapid 

 discernment of D. aurita. Only in one case — a young female — ■ 

 were these face-markings very distinct, as yellowish longitudinal 

 stripes. 



All the figures I know of D. cancrivora represent this animal 

 with very indistinct face-markings (compare Burmeister, pi. iv. ) ; 

 and on the other hand the authors always draw D. azarce and 

 D. albiventris with most conspicuous face-markings (</. Bui'meister, 

 pis. i., ii.). In regard to the colour of the ears, I repeat what I 

 said in my little work on the Mammals of Brazil ', that D. aurita 

 and D. cancrivora have uniformly dark-brown coloured ears, and, 

 so far as concerns the first, I had full occasion to make this state- 

 ment on the living animal. 



Dentition. — Much has been written about the dentition of 

 Didelphr/8, and the literature has been thoroughly co-ordinated by 

 Mr. H. Winge, ' Pungdyr,' p. 113 and p. 122 et seq. For the 

 present I have no mind to write at all fully on this matter and I 

 will restrict myself to the remark that abnormalities are so rare 

 that I have never yet seen a single skull of an adult I), aurita 

 with a formula other than strictly |j '\'\\. This contrasts some- 

 what with some of our Braziliau carnivorous animals; the Tayras 

 (Galictis), for example, often show some symmetrical abnormalities 

 in the number of molars. 



2. Metachibus qttica. 



Of the subgenus Metachirug, established by Burmeister in 1856, 

 no other form was observed by me in the Serra dos Orgaos than the 

 common " Quica" {Didelphys opossum, Linn., of Thomas), which 

 is frequently seen in the forest as well as in the neighbourhood of 

 Tazendas. In snares destined especially for Kodents I constantly 

 found this beautiful but stupid and incautious marsupial. My 

 collection contains about a dozen individuals from this locality. 

 There is great uniformity in the general colour: all show the 

 same clear glistening grey above and a yellowish belly. I never 

 met with a female of the reddish tone indicated by Burmeister, 

 pi. viii. 2 I may mention here that some years ago I took an 



ones (fi (5, 5 £) and 45 white ones (22 rf , 23 $), and that among !' young 

 individuals, still contained in the mother's pouch, he observed one black, two 

 mixed, and six white ones. This observation, together with inv own above 

 cited (young male and half-grown female), proves that Burmeister is wrong 

 when he denies the existence of young JJideljihi/s with white bristle-hairs with 

 the words : — " Kein junges Thier hat weisse Grannen " (Erlaut. p. 58). 



1 E. A. Goeldi, ' Os mammiferos do Brazil.' Rio de Janeiro (Alves e Cie.), 

 1893. Monographias brazileiras, vol. i. 



2 I confess that I was doubtful as to the existence of such reddish " Quicas" 

 until recently. Almost at the moment of posting these notes, my family in 

 Rio de Janeiro gave me on my return from Oolonia Alpina a great surprise l>\ 

 a present of a nice young male "Quica,'' very well corresponding to 

 Burmeister' s figure. Its eyes are also reddish brown(cherry-colour), soinew hat 

 like those of an albino, and its tail is throughout, but especially on the basal 



