2.26 Zoological Society : — 



in. Kn, 



Length of the tragus 2^ 



of the fore-arm 1 7 



of the longest linger 2 7^ 



of the fourth finger 1 10 



of the thumb 4 



of the tibia 8| 



of the foot and claws b\ 



of the OS calm 8 



Expanse of wings 11 6 



In colour this species very closely resembles the last, but, besides 

 many minor points of distinction, the great length of the tail in the 

 former will at once be sufficiently distinctiye. 



I have now described all the s{>ecies that I am able with certainty 

 to refer to this group ; but there are two others described by Major 

 Le Conte in the * Journal of the Academy of Natural Sciences of 

 Philadelphia' for 1855, characterized by the same formula of denti- 

 tion as in Lasiurusy but which appear nevertheless to have the other 

 parts as in the more ordinary Bats. 



One of these — Fesp. pallidus, Le Conte, — the writer says, has 

 only four incisors in the lower jaw, — altogether an anomalous cha- 

 racter, if not due to some accidental cause. 



The other species is the Vesp. crepuscularis of the same »aturalist 

 {V. creeks, F. Cuv.), which, while possessing only two upper incisors, 

 precisely as in Lasiurus, has yet all the other characters similar to 

 those of Fesp. Carolinensis, — a species clearly appertaining to that 

 division of the genus Scotophilus which constitutes Section b. of the 

 genus Fesperugo of MM. Keyserling and Blasius. 



It would appear from this that the number and form of the inci- 

 sors in the upper jaw do not furnish a very valuable generic cha- 

 racter ; and when we find another species from India, not only dif- 

 ferent in its fonns from Lasiurus and Nycticejus (so called), but 

 also differing from the above-mentioned Fesp. crepuscularis in all 

 respects save in the upper incisors, which are similar, we are quite 

 justified in regarding this as a character of subordinate value in the 

 arrangement of this difficult group of animals. 



The Indian species to which I allude is referable, as far as external 

 form is concerned, to that section of the genus Fespertilio which has 

 been called Cappacinius by Prince Charles Lucien Bonaparte, and 

 Trilatitius by Dr. Gray. It is closely affined to the Fesp. Tasma- 

 nensis of the latter zoologist, and may perhaps prove identical with it. 

 Besides the species given in this Monograph, there are several 

 others differing materially from them, and from each other, but 

 which have the tail-membrane hairy. As instances, may be cited 

 Fesp. noctivaganSy Le Conte {V. jndverulentus, Temm.), Lasiurus 

 Pearsoniiy Horsf. (closely affined to the Fesp. emarginatus* of the 



* In alluding to this species, I may mention, that it is the Fesp. emarginatu» 

 of continental writers to which I refer, — a well-marked species very similar in ap- 



