CHEIROMELES TORQUATUS. 



affords a striking affinity ; this is very satisfactorily illustrated by a comparison of 

 the Cheiromeles torquatus with the Nyctinomus iEgyptiacus, figured in the Mem. 

 de rinstitut d'Egypte, &c. by M. Geoffroy. Seventhly : — The tail has likewise essen- 

 tially the same structure, though it appears of greater dimensions in Cheiromeles 

 from the membranaceous covering with which it is surrounded. Eighthly : — A very 

 striking resemblance between Nyctinomus and Cheiromeles, and which, as far as my 

 observation extends, has nothing analogous in the other genera above enumerated, 

 exists in a brushlike appendage to one or to several fingers. In Cheiromeles it 

 occupies the exterior side of the thumb, and has already been described in detail. In 

 Nyctinomus both the exterior fingers, as well that which corresponds to the thumb, as 

 the little finger, are provided with an appendage which has the following character. 

 A series of delicate hairs, about one line in length, extends along the whole of the 

 exterior side both of the thumb and of the little finger ; a few hah-s of a greater 

 length are scattered through these, and likewise stretch forward, and spread over the 

 claw. These hairs rise nearly erect or vertically from the finger, and are not directed 

 horizontally outward, as in Cheiromeles. The separate hairs are bent or hooked at 

 the extremity ; their colour is silvery gray. This regularly defined series of hooked 

 hairs must not be confounded with the long lax hairs which are observed on all the 

 fingers of the Nyctinomi, and which, according to M. Geoffroy, must also be placed 

 among the generic characters. These long irregular hairs are likewise observed in 

 Cheiromeles, independent of the appendage of the thumb. It should be remarked, 

 that in Nyctinomus the metatarsal bones of the thumb and of the little finger are 

 perfectly uniform in size, slightly exceeding those of the interior fingers. 



From the preceding comparison it clearly appears, that in a natural arrange- 

 ment of Vespertilionidfe, Nyctinomus should immediately follow Cheiromeles. I 

 am not prepared to state the order in which the other genera belonging to this group 

 above enumerated, should be placed; but Cheiromeles doubtless stands at the 

 head of it, as possessing an affinity to the Prosimii or Macrotarsi of Illiger, not 

 only in the structure of the thumb and its lengthened nail, but also in the carni- 

 vorous grinders, which are provided with projecting points. These considerations 

 suggest a new disposition of the Vesper tilionidae, but this remains for future inquiry ; 

 my immediate object has been to give the history of Cheiromeles torquatus, and to 

 illustrate its affinities in this family. 



On the Plates annexed to this article, an anterior and posterior view of Cheiro- 

 meles torquatus is exhibited. In the former the animal appears of natural size ; in the 

 latter it is reduced nearly one-half: to this Plate the following illustrations are added. 



