34 Mammalia. Cheiroptera. 



IV. CHEIROPTEEA. 



The Skull. In most insect-eating Bats the Svperoecipital slopes 

 backwards, and contributes to the crista continued forward by the 

 interparietal and parietal bones. The Occipital Foramen \B\Qxj\^Yge 

 in most of the Order. The Mastoid is large and distinct, giving 

 attachment to the tympanic. The zygomatic parts of the Squamosal 

 and Malar are slender. The Frcemaxillaries are very small : in some 

 {e.g. Rhinoloplms) they are wanting. The Orbital and Temporal fossm 

 communicate freely. The Tympanies are very slightly connected 

 with the skull. In the frugivorous Bats (Pteropus) the Malar is 

 situated as in the Insectivorous Erinaceida). 



The Vertebral Column. The Spinal Column gradually diminishes 

 in size, from the cervical to the sacral region. The neural spines 

 are generally of very small size in all vertebrae beyond the dentata. 

 The Sternum is carinate. 



In Pteropus the keel of the large manubrium stemi is produced into a process 

 at each angle. 



Scapular Arch and Appendages. The Scapula is generally broad. 

 The Clavicle arched, long, and strong. The Humerus and Radius long 

 and slender. The Ulna rudimentary or absent. The Finger-bones radi- 

 ate widely from the wrist, the thumb is short, and furnished with a 

 long claw. The Metacarpals' oi the four clawlees fingers are exces- 

 sively elongated; these, together with the bones of the arm, are, in 

 the natural state, united by a delicate leathery membrane. 



Pelvic Arch and Appendages. The Pelvis is feeble and slender. 

 The narrow subcylindrical Ilia coalesce with the sacral vertebra?, 

 and are parallel with the spinal column. The pubis is continued in 

 a line with the ilium to the ' symphysis,' which is generally but 

 slightly closed in the male, and remains open in most female bats. 

 The Sind Limbs are short. The Fibula is absent or rudimentary. 

 The Heel has generally appended to it a long and slender styliform 

 bone, which helps to sustain the Caudo-femoral membrane. 



v. RODENTIA. 



The Skull. The confluence of the elements of the epencephalic 

 arch* is late. The squamosal maintains its individuality ; and fre- 

 quently has developed from it long compressed lamina, which serve 

 to clamp the tym^^anic and mastoid, or one or other of them to the 

 bide of the cranium. The malar is suspended in the middle of the 



* ' Occipital hone ' of Anthroptomy. 



