INTRODUCTION. XXXI 



the islands of the Low Archipelago. But they are present in most 

 other oceanic islands of any extent ; few of the islands of the Pacific 

 west of the Low Archipelago are without some species of the frugi- 

 vorous PteropodiclcB, even the small Savage Island, south-east of the 

 Navigators' group, being inhabited by Pteropus keraudrenii. 



Of the six families into which the Chiroptera are divided, two 

 only (the Vespertilionidoe and Emhallonuridm) extend into both the 

 Eastern and Western Hemispheres ; and even of these the species of 

 the latter family inhabiting America are quite distinct from those of 

 the Old World, and the genera nearly so, Nyeiinomus alone being 

 common to both ; while of the sixteen genera of Vespertilionidce, 

 two only {Yespertilio and Vesperugo) are generally distributed, and 

 one species alone (Vesperugo serotinus) is certainly known to inhabit 

 both the Old World and America *. 



It is worthy of note that, of the single genus of Emhallonuridce 

 which is common to both Hemispheres, four species only out of 

 twenty-one inhabit America, and these are all closely related to one 

 another, and very far removed from any of the Old-World species. 



Of the remaining families, the Pteropodidce, BMnohphklix, and 

 Nycteridce are strictly limited to the Old World, the Phyllostomidce 

 to America. 



The Eastern and Western Hemispheres are therefore, on the 

 whole, eminently distinct in their Chiropterous fauna ; and it wlR 

 be found, when we come to examine the distribution of the genera 

 of each family, that each zoological region has its characteristic 

 species also. 



The Pteropodidce are distributed throughout the Ethiopian, 

 Oriental, and Australian Eegions (except Tasmania and New 

 Zealand) ; but of the genera one only, Cynonycteris, extends 

 throughout all these Regions. EpomopJiorus is strictly limited to 

 that part of the Ethiopian Region included within the contiuent of 

 Africa. Gynopterus is almost limited to the Oriental Region, a 

 single anomalous species, C. latidens (which differs widely from all 

 the other species in the form of its teeth), being found in the 

 Moluccas. Eonycteris is, as yet, known from the Indo-Malayan 

 Subregion alone; Macroglossus has the only species of this family 



* This fact has not been previously noticed. It has hitherto been generally 

 understood among zoologists that the American species of Bats were totally 

 distinct from those of the Old World. It is probable that Vesperugo abramus 

 and V. borealis also extend into America (see remarks on the distribution of 

 these species, infra, pp. 193, 203, 229). 



