X INXKODUCTION. 



me to make a personal examination of every typical specimen of 

 the present group of animals now preserved in Europe. But above 

 all my most particular thanks are due to the Marquis Giacomo 

 Doria, of the Museo Civico, Genoa, both for much personal and 

 epistolary assistance, and, especially, for the kindness with which 

 he has granted me the loan, without limit of time, of the whole 

 collection of Papuan Marsupials there preserved. That collection 

 contains so many types and well-preserved series of specimens 

 belonging to some of the most difficult groups of Marsupials, that 

 without their help it would have been almost impossible to have 

 worked out satisfactorily such obscure but important Australasian 

 families as the Peramelidm and DasyuridcB. Por other most useful 

 and timely loans of specimens I am indebted to Dr. E. Collett, of 

 the Christiania Museum, to Mr. De Vis, of Brisbane, and to 

 Mr. Frederick Moore, of Liverpool. 



Lastly, of friends at home I must express my acknowledgments 

 for advice and assistance in various ways to Prof. Stewart, Mr. P. 

 L. Sclater, and to Mr. E. Lydekker, whose knowledge of fossil 

 Marsupials has frequently been of considerable service to me. 



OLDHELD THOMAS. 



British Museum (N. H.), 

 Aug. 20, 1888. 



