466 



DH. P. CHALMERS MITCHELL ON LONGEVITY AND 



Peramelid^. 



Feragale Za^/oiffsf Rabbit-eared Bandicoot). 

 Perameles obesida (Short-nosed ,, ). 



No. of 

 liidiv. 



Av. duv. 

 in months. 



19-8 



Max. dnr. 

 in months. 



17 



These little omnivorous and carnivorous marsupials show low 

 maximum and average durations. Tliey have a capacious hind-gut 

 and Cfficum in proportion to their size. They have been kept in 

 small cages in a heated house, without access to fresh air, and 

 have not done well. 



DASYURIDiE. 



Thylacinus cynocephalus 



No. of Av. dur. 

 Indiv. in months. 



7 43 



52-5 

 33 



37 



9,8-p; 



Max. dur. 

 in months. 



103 



61 



82 



75 - 

 82 



(Tasmania!! 7 

 Wolf). 



Sarcophilus tirsinus (Tasmanian Devil) . 7 



Basyurus^ whole genus 44 



2). 'OT«cit?aiMS (Spotted-tail Dasyure) ... 5 



i). mvemmts (Mavxge's „ ) 39 



Compared with Carnivora of similar sizes, the maximum 

 duration of these carnivorous marsupials is not so high, sug- 

 gesting possibly a low potential longevity. On the other hand, 

 the average duration is rather better in proportion, which may 

 be evidence of a greater viability. The conditions under which 

 they have been kept are similar to those of trtie Carnivora : larger 

 forms like the Thylacine have been given unheated shelters with 

 access to the open air ; the smaller forms, for the most part, 

 have been confined in artificially warmed houses. 



DiDELPHYIDiE. 



No. of 

 Indiv. 



Didelphys, whole genus 92 



D. azarce (Azara's Opossum) 20 



D. cancrivorus (Crab-eating Opossum). 31 



D. cinereits (Cinereous 



D. crassicaudata (Thick-tailed 



B. lanigera (Woolly 



D. murina (Murine 



D. nudiccmdata (Rat-tailed 



D. opossum, (Quica 



B. philander (Philander 



D virginiaiia (Virginian 



1 

 5 

 6 



2 

 2 

 9 

 4 

 12 



Av. dur. 

 in months. 



10-8 



13 

 5 



16 



19 



1- 



9 



11 



4- 



Max. dur. 

 in months. 



85 

 28 

 85 



5 

 28 

 53 



2 

 14 

 22 



9 

 16 



The Opossums, which are omnivorous and carnivorous, display 

 low maximum and average durations, and so far as this evidence 

 goes would appear to have a relatively low potential longevity 

 and a poor viability. On the other hand, they have been treated 

 as animals requiring protection from cold at all costs, and have 

 been kept in artificially warmed houses without access to the 

 open air. 



