488 THE VERTEBRATE SKELETON. 



In the RODENTIA (fig. 100, C) the malleus is generally 

 characterised by a very broad manubrium. In many genera 

 such as Batfiyergus, and most of the Hystricomorpha such as 

 Hystrix, Chinchilla and Dasyprocta, the malleus and incus are 

 ankylosed together. 



CARNIVORA. In Carnivora vera the most striking feature 

 of the malleus is the occurrence of a broad lamellar expan- 

 sion between the head and neck and the processus longus. 

 This however does not occur in some Yiverridae. In the 

 Carnivora vera the incus and stapes are small as compared 

 with the malleus, but in the Pinnipedia they are large. In 

 the Pinnipedia the auditory ossicles have a very dense 

 consistence, and except in the Otariidae are very large. The 

 stapes frequently has no canal, or only a very small one. 



In INSECTIVORA the characters of the auditory ossicles are 

 very diverse. Many forms such as shrews, moles, hedgehogs, 

 and the Centetidae have a low type of malleus resembling that 

 of Edentates. Chrysochloris has very extraordinary auditory 

 ossicles. The head of the malleus is drawn out into a great 

 club-shaped process, the incus is long and narrow, and differs 

 much from the ordinary type. 



In CHIROPTERA the ossicles and especially the malleus much 

 resemble those of shrews. The stapes is always normal in 

 character, never becoming at all columelliform. 



PRIMATES. In Man and the Anthropoid Apes the malleus 

 has a rounded head, a short neck, and the manubrium, a 

 processus longus and a processus brevis. The incus consists of 

 an anvil-shaped portion from which arises a long tapering 

 process. The stapes has diverging crura and consequently a 

 wide canal. The crura in other monkeys do not diverge so 

 much as in man and anthropoid apes. The New World monkeys 

 have no neck to the malleus. 



