PREFACE TO THE FOURTH EDITION. 



THE alterations introduced into the present edition consist chiefly 

 in changes of nomenclature, and in references to the more im- 

 portant additions which have been placed on exhibition since the 

 previous issue of this Guide : such as specimens of the Two-humped 

 Camel of Central Asia, of the Pigmy Hippopotamus of Liberia, 

 of a fullgrown ram of Hodgson's Sheep ; skeletons of the Killer- 

 Whale and Grey Whale of the North Pacific; the recently 

 discovered Mole-like Marsupial from Central Australia. The 

 opening-up of the countries of Eastern and Central Africa has 

 yielded several new and interesting forms of Antelope, whilst 

 Mr. St. G. Littledale has enriched the collection with a pair of 

 the European Wild Bison, a series of Polo's Sheep, and several 

 other large game-animals, all obtained by himself during his 

 expeditions into the Caucasus and Central Asia. Finally, the 

 exhibition of heads and horns of big game will be found con- 

 siderably enlarged by a magnificent donation of A. 0. Hume, 

 Esq., C.B., who has presented to the Trustees the whole of his 

 Collection of Indian Mammals. 



A. G. 



Zoological Department, 



July 3, 1892. 



