Mr. U. F. Toiiu's un the genus Nyctophilus. 



385 



The crania of tlicse species present the following dimensions : — 



Length from the coiulyloiil fossa to 

 the anterior margin of the max 

 illar)' bone ... 



Lengtii from tlic hinder margin o 

 the parietal hones to the anteriorj 

 margin of tlie maxillary bone 



Breadth across zygomatic arclics...' 



Greatest breadth of the cerebral 

 region | 



Greatest l)readth of the facial de-] 

 pression 



Length of the bony palate 



Length of the series of teeth of the! 

 upper jaw, exclusive of the in-' 

 cisors 1 



Space between the points of thej 

 upper canines 



Space between the posterior molars 



Greatest length of the lower jaw... 



Breadth of the lower jaw, taken in 

 a vertical direction from the co- 

 ronoid process 



Length of the series of teeth in the 

 lower jaw, exclusive of the in- 

 cisors 



Space between the points of the 

 lower canines ' 



N. Geoffrnyi. 

 in. Iin>'a. 



4^ 



If 



2 



5 



1-1 



I am especially indebted to Mr. Gould for having placed at mv 

 disposal materials which have been of great service in making out 

 the species treated of in the present memoir. The use of specimens 

 collected by him, with the knowledge of their exact localities, has 

 been a great assistance in more respects than one. Besides afford- 

 ing evidences leading to the determination of several species, in a 

 genus formerly supposed to be represented by only one, it has also 

 afforded materials which have tended in some measure to the deci- 

 sion of what constitutes a species and what is only a variety. 



It is a well-known fact, that many mammals and birds inhabiting 

 India are found to vary remarkably in size and colour in different 

 parts. Thus if we take some of the Bats as an instance suitable for 

 the present occasion (and we might equally adduce many other 

 manmials and birds) *, we shall find those inhabiting South India 

 and Ceylon smaller and darker in colour than those occurring more 

 northward ; and on further examining the matter, we shall further 

 discover that they are referable to the same species, and that interme- 

 diate examples may be found at intermediate localities. Not only 

 in external conformation are they similar in their proportions, but 

 also in the details of their osseous system. The skulls of these va- 



* Among the Bats may be particularly noticed Cynopteris marginatus, Scoto- 

 philus Coromandelicus, and Vespertilio papilloms. See Dr. Kelaarfs ' Fauna 

 Zeylanica,' and the appended notes by Mr. Blyth.as also various notices of Mam- 

 malia bv the latter gentleman in the Journal of the Asiatic Society. 

 Ann. ^- Mag. N. Hist. Ser. 3. Vol. i. 25 



