descriptions of the Bpecies themselves being often quite sufficient, 

 supposing that they had been more carefully divided into groups. 



Two principal works which demand study in working OUl the -|><- 

 eirs of VespertiUonida— -Temminck's Monograph, and Wagner's 

 Supplement to the work of Schreiber — are of this description. 

 Whilst giving a pretty complete account of each species, the generic 

 definition is, in consequence of the gnat disparity in the characters 

 of the different species, necessarily so vague as to he nearly useless. 



Scarcely more valuable to the investigator are lists of genera and 

 species without accompanying descriptions, or having these so ex- 

 cessively brief as to be wholly unavailable in distinguishing species. 



I have therefore, while bringing together specie-, which fall easily 

 under a generic definition, considered it advisable to add also a de- 

 scription of each, although they may have been before described, or 

 be even well-known species. 



By adopting this method I am enabled to give much more com- 

 plete descriptions than have hitherto appeared, because they are of 

 a more comparative nature, and are therefore more serviceable in the 

 discrimination of allied species. 



With regard to the synonymy of the several groups, it is as com- 

 plete as I have been able to make it, but is I believe very imper- 

 fect. In all instances care has been taken to exclude such names 

 and references as I could not either personally test by the examina- 

 tion of unquestionable species, or by the comparison of figures and 

 descriptions agreeing with such accuracy as to leave no reasonable 

 doubt as to their identity. 



This explanation appeared necessary previous to bringing before 

 the Society successive papers in which but very few of the species 

 are new, and many old and well-known ones are described at Bome 

 length. 



The name of Kerivonhi was first given by Boddaert * to a species 

 of Bat which had before been described by Pallas -f by the name of 

 Vetpertiltopictiu — a name singularly appropriate for an animal with 

 the bright red fur and membranes, and the peculiar distribution of 

 the colour on the latter, which characterizes the species. 



Boddaert's specific name having given way to that of Pallas, has 

 been taken up by Dr. Gray J, and used in a generic sense, be 

 having perceived that the species differed considerably from most 

 other representatives of the genus Vetpertilio. 15m lb-. Gray, 

 placing great reliance on the importance of a single character, has 



arranged with it BOme species, the affinity of which the subsequent 



examination of a greater number of species has not corroborated. 

 In these investigations others have been discovered which ben verj 

 close generic resemblance to the original one, V. pictus, whilst 

 some of those which have been associated with it prove, on the 

 contrary, to be by no means closely affined. 



* Elenchus Animalium, vol. i. list (Ju.idnip. p. 7", No. in. l; 

 t Spicilegia Zoologica, iii. p. 7,177 1. 

 : Am.als and Max. Nat. Hilt 1848, p 



