X V INTUODrCTION. 



three joints each — long and cylindrical. The pelvis is slender and 

 narrow. The ilii are elongated, not widened, and markedly con- 

 vex on outer surfaces ; ischia relatively large, and converging ; 

 pubis rather slender. The ossa innominata are readily disunited 

 at symphysis, their union to the sacrum being firmer. Obturator 

 foramen large and elliptical. Jioth. femu7' and tibia are long cylin- 

 drical bones, presenting no features of interest. The Jibiila is 

 slender, acuminate and imperfect ; it arises from the base of the 

 tibia, and terminates midway up that bone. By the partial ever- 

 sion of the lower extremity it appears to lie to the wner side of 

 the tibia. The toes are five in number and armed with sharply 

 curved claws ; the calcaneum is enormously developed as a spicula 

 of bone, running obliquely downwards and inwards towards the 

 tail, and inclosed within the border of the interfemoral membrane. 

 The termination of this bone is abrupt in some species, in others 

 its extremity blends with the free edge of the membrane. The tail 

 is composed of nine joints in the majority of bats, which diminish 

 in width from above downwards ; the tip of the tail may or may 

 not be included in the interfemoral membrane. 



Mr. Thomas Bell, in reviewing the osteology of the bat, uses 

 the following language : — 



" The whole of this structure is so perfectly adapted to the 

 peculiar habits of the animals as to require no comment. The 

 great development of the ribs, sternum, and scapula for the attach- 

 ment of strong muscles of flight ; the length and strength of the 

 clavicle ; the extension of all the liones of the anterior extremity, 

 all admirably tend to fulfil their obvious end." — Cyclopaedia of 

 Anat. and Phys., art. Cheiroptera. 



The digestive apparatus is very simple, as might be supposed 

 from the nature of the food upon which these animals subsist. 

 The stomach is simple, with small fundus. The intestine is short, 

 measuring but one and a half times the length of the body, and in 

 many species without a ctecum. 



The nervous system is highly developed, especially the special 

 senses of hearing and of touch. The ears, both internally and 

 externally, are highly perfected. The cochlea are disproportion- 

 ately large as comi)ar('d with the size of the semicircular canals. 

 The ampulke, as already seen, are very large. To this osseous 

 structure, for the reception of sound, is added the complicated 

 auricle with which all insectivorous bats are provided. These 



