402 DI?. F. ,\. GOELDI OS THE [JllllO 5, 



given, together with the measurements, agree tolerably well with 

 those presented by my specimen. The basal length of the skull 

 of an adult individual is equally mentioned as being 32 mm. ; and 

 as " habitat " Mr. Thomas gives " Central and Eastern Brazil.'' The 

 individuals in the British Museum are from " Kio de Janeiro." 



Ou the other hand, D. elegant is said to be a Chilian form. 

 Mr. Thomas indicates as its habitat " South Brazil and Chili," but 

 in the list of the British Museum individuals of D. elegant I 

 cannot discover any Brazilian locality. 



4. Micoureus pusileus. (Grymaomys a/jilis.) 



A second member of the subgenus Micoureus, frequently 

 observed by me here in the Serra dos Orgaos, is M. pnsitlvs, 

 almost impossible to be confounded with any other little Didelphys, 

 except perhaps D. lepida. recently described from the Amazons. 

 Its bright rufous fur, its very dark and conspicuous eye-markir.gs, 

 and strongly- developed " vibrissa;" readily distinguish this most 

 graceful and really very beautiful " pygmy Opossum." Burmeist er's 

 figure on plate xv. is not entirely satisfactory, as the rufous general 

 colour is not sufficiently marked. 



Mr. O. Thomas says (p. 354) about the smaller Didelphyidse, 

 especially of the subgenus Peramys: "The habits of the species 

 are as yet undescribed, but they are probably tar less arboreal than 

 the other Opossums." I think this observation is applicable also 

 to the smaller forms of the Micoureus-growp : and as I have had 

 considerable opportunities of observing the habits of these animals, 

 both in freedom and in captivity, it may be of interest to relate some 

 of the most peculiar features. 



Everybody acquainted with the European Dormouse (Mus- 

 cardinus avellanarius) will easily gain an idea of Micoureus pusillus. 

 In spite of the different orders they belong to, the likeness of the 

 two animals is a most striking one as regards the size, the fur- 

 colour, the movements, and the confident demeanour. 



Micoureus pusillus is often brought to me by our workmen when 

 occupied in new " rocas." Persons not knowing about the common 

 Brazilian system of agriculture, may learn that a wise law obliges the 

 owner to clear of forest a certain space around the homestead, the 

 trees being afterwards burnt when dried by the sun (" derubada"). 

 The continued line of accumulated sweepings (dry leaves and 

 branches) formed by this process is called " aceiro." I found that 

 these " aceiros," especially when running in the neighbourhood of 

 some watershed, are a favourite resort of our marsupial. 



During the day it will rarely be seen, and only some accident 

 will oblige it to leave its hiding-place, but only for an instant until 

 it has again found a refuge. Such an accident is the fire, when 

 the dry " derubada "' is kindled. AVhen made prisoner it does nut 

 oppose much resistance nor bite severely. Placed in a hollow tube 

 of bamboo, it bears easily a journey of several hours. 



Several times I had specimens of Micoureus pusillus of both 

 sexes alive for some time in my study. In order to obtain 



