108 PSEUDOCHIRUS. 



NOTE XIV. 



ON TUK SIM^^CIES OF THE PHALANOER-OENUS 

 PSEUUOCHIKIS. 



BY 



Dr. P. A. JENTINK. 



5 Marcli 1884. 



Pseudochiriis is a well-defined genus of Plialangers, which, 

 vip to this time, embraced three species: cookii , hernMeimi 

 and alhertisii. 



PseudocJiirus viverrinus Ogilby (1837), from Van Die- 

 men's Laud , is regarded as specifically distinct from Ps. 

 cookii Desmarest (1817), from the Australian Continent. 

 They are also separated by Gould (Mammals of Austra- 

 lia, 1863), who stated that the island examples are of a 

 larger size and always dressed in a softer and longer fur 

 and who said, that for the present he regarded them as dis- 

 tinct. Gould remarked an analogical phenomenon in Tricho- 

 surus lemurinus or vulpinus from the Australian Continent and 

 Trichosurus fuliginosus from Van Diemen's Land. He says 

 „the skins of the Island and Continental Animals are both 

 made into sleeping rugs , but the former are esteemed so 

 much more highly, that a rug formed of them is consi- 

 dered worth three times the price of one of the latter." 

 A conscientious comparison of the skulls however shows 

 that there is no trace of difference between these parts of 

 the continental and of the island forms, neither in form 

 of skull nor in dentition. In my opinion such facts are 

 proofs to illustrate the great variation of a certain species 

 within certain limits ; these variations depend upon external 

 causes, as there are: locality , climate , food a. s. o. The study 

 of such influencing circumstances learns us the laws of nature. 



^otes from the Leyden IMuseum , Vol. VI. 



