45 



tion as in Lasiurus, but which appeaT nevertheless to have the other 

 parts as in the more ordinary Bats. 



One of these — Veep, 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 T~e$p. erepuseularis of the same naturalist 

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

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

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

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

 genus Vesperugo of MIL 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 forms from Lasiurus and Xycticejus (so called), but 

 also differing from the above-mentioned Vesp. erepuseularis 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 Vespertilio which has 

 been called Cappaeinius by Prince Charles Lucien Bonaparte, and 

 TriJatitius by Dr. Gray. It is closely affined to the Vesp. 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 

 Vesp. noctiragans, Le Conte (V. pulverulentus, Temm.), Lasiurus 

 Pearsonii, Horsf. * (closely affined to the Vesp. emarginatus of the 

 continent of Europe), and Vesp. suillus, Temm., called Murina 

 suillus by Dr. Gray, and Xoctilinia Lasyura by Mr. Hodgson. 



From this it must be evident that this character is only of generic 

 value when associated with others of greater constancy, and it is only 

 by the characters taken collectively that the groups can be truthfully 

 defined. 



The form of the head, the muzzle, and the nostrils, of the ears and 

 the tragi, the extent of the membrane in reference to the hinder ex- 

 tremities, the quality and distribution of the fur, the number and 

 form of the upper incisors, and more than all, the general conforma- 

 tion of the cranium, supply the means by which the Lasiuri may be 

 recognized and associated. 



' * In alluding to this species, I mav mention, that it is the Tesp. emarginatus 

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

 pearance to Lasiurus Pearsonii, hut not more than half the size, and with less 

 hair on the interfemoral memhrane. The so-called British species is, I believe, 

 no other than Tesp. mystacinus. 





