18G MU. A. H. a. BORAN ON THE MOEPHOLOGT OF 



lu the Dssicula of the Insectivora no constant positive character 

 can be found. These bones are most specialized in Ohrys'ocTiloris. 

 Careful examination shows that tbe singular malleus in this genus 

 is modified rather from the higher or anthropoid form than from 

 the more central laminated type. The ossicula of Galeopithecus 

 are very generalized ; iil its malleus it approaches the Macrosce- 

 lidse, in the incus it resembles Tupaia ; in the latter the malleus 

 assumes the neckless character common among the Cebidae, and 

 observed in some Lemurs and in Sciurus. Taken as a whole, the 

 ear-bones of Tiipaia are higher in type than those of any other 

 animal in this order. 



In the Macroscelidse the extremely constricted neck of the 

 malleus with its narrow lamina and its processus gracilis running 

 straight forwards to the Glaserian fissure are highly characteris- 

 tic ; but in Fetrodromus the malleus more resembles that of /S'orea? 

 than the same ossicle in Macroscelides and Shi/neJioct/on. 



In the Soricidse, Myogalidse, Talpidse, Centetidse, and Erina- 

 ceidiB one common feature exists, a malleus with a wide lamina, 

 and a processus gracilis united to the tympanic ring after the 

 fashion of the Marsupials. The processus brevis of the incus is 

 always ill developed except in the Centetidai and Qymnura ; the 

 intercrural aperture of the stapes is wide. In the Shrews tlie 

 malleus bears both a processus muscularis and a peculiar orbicular 

 apophysis, as in Mus ; this spherical process in Myogale appears 

 to replace functionally the processus muscularis, which is absent 

 in that genus. 



In the Talpidse the malleus of Condylura most resembles that 

 of Sorex ; but its orbicular process serves as a processus muscu- 

 laris, as in Myogale. The mallei in Talpa and Scalops closely re- 

 semble each other ; but the incus of Scalops has not the broad 

 channelled processus longus seen in Talpa and Condylura. In 

 the Erinaceidse and Centetidse the malleus has a broad processus 

 gracilis perforated to transmit the chorda tympani nerve. The 

 processus muscularis and an ill-developed orbicular apophysis 

 coexist. 



The ossicula of the Chiroptera resemble those of the Soricidse 

 and allied Insectivora very strongly, except in Pteropus, where 

 the malleus is of a rather lower type. A well-developed proces- 

 sus muscularis is always found in the insectivorous Bats ; in 

 PhyllorMna and other genera there is another process accessory 



