CHEIROMELES TORQUATUS. 



position. The auricle is very broad at the base, and extends along the skull from 

 the eyes towards the neck : posteriorly it forms a curve, which rises again to a large 

 trao-us, placed exteriorly below the auricle. It is about two lines long, semicordate, 

 obtuse, and continued anteriorly into a small membranaceous border, extending 

 towards the angle of the mouth. The auricle itself is oblong, nearly obtuse, simple 

 at the anterior, and involute at the posterior margin. The general direction of the 

 ears is upward and outward. The base of the auricle leads to a tube of great trans- 

 verse dimensions. Indeed, the great extent of the internal ear is one of the peculiarities 

 of Cheiromeles. The diameter of the entrance to the cavity of the tympanum is 

 likewise of extraordinary size : in preparing the skull, the bones' of the ear were easily 

 separated for examination, and, in comparison with those of the human ear, were 

 found of enormous dimensions. In the skull all the parts belonging to the ear are 

 greatly developed, and the cochlea in particular is of vmcommon extent. The texture 

 of the OS petrosum was apparently very loose. 



The eyes are small, and partially concealed. The eyelids are surrounded by a 

 minute circle of rigid hairs, regularly disposed. The anterior margin of the auricle 

 is adapted to afford a partial covering and protection to the eyes. The front teeth in 

 the upper jaw reseiuble a section of a cone through the axis : they are of great strength ; 

 those in the lower jaw are comparatively small. The canine teeth above have a sharp 

 edge along their internal angle, but in other respects these teeth are of moderate size, 

 and of simple structure. The large grinders agree in aU essential points with those 

 of Nyctinomus ; but this agreement will be shewn more fuUy in the comparison of 

 Cheiromeles with that genus. 



Of all the Vespertilionidas with which I am acquainted, the Cheiromeles torqua- 

 tus has, next to the Nyctinomi, the greatest extent of wing. The phalanges of 

 the third and fourth fingers are remarkably long and delicate. Our animal possesses a 

 peculiarity of structure at the union of the arm with the body, similar to that which 

 has already been observed, in different degrees of development, in several Vesper- 

 tilionidse. It consists of a deep cavity, extending from the axiUa and neighbouring- 

 parts, towards the spine and the hypochondrige. Anteriorly it is bounded by a 

 membrane extending from the arm to the pectoral muscle, and then passing to the 

 sides of the body, and uniting with the common integuments : the expanded mem- 

 brane of the arms and body is its posterior limit. The cavity thus formed is about an 

 inch deep, and nearly two inches long ; it is lined with a very delicate membrane, 

 and its uses will be pointed out in the sequel. A structure analogous to this occurs 

 in the Pteropus palliatus of Geoflfroy, and in the genus Cephalotes. In the Saccopteryx 



