154 THE SKULL. [chap. 



The postorbital processes of the frontals are long and 

 pointed, and partially define the orbits behind ; but there 

 is usually no corresponding ascending process from the 

 zygomatic arch, which is long and slender, and mainly 

 formed by the processes of the maxillary and squamosal, 

 the malar being a splint-like bone attached to their under 

 and outer surface. The lachrymal foramen is situated outside 

 the margin of the orbit. The nasals are long and narrow, 

 and often ankylose together in the middle line. The pre- 

 maxillse are small. The palate is elongated backwards ; 

 the horizontal plates of the palate bones being large and 

 early united in the middle line, without defects of ossifica- 

 tion. The pterygoids are small. . There is no alisphenoid 

 canal. The glenoid fossa is broad and shallow ; the post- 

 glenoid process very little developed, and with a venous 

 foramen behind it. The tympanies are very slightly con- 

 nected with the neighbouring bones, and are consequently 

 nearly always lost in macerated skulls. A wedge-shaped 

 portion of the mastoid appears on the outside of the skull 

 between the squamosal and the exoccipital. The par- 

 occipital process is long and rather slender, and directed 

 downwards and backwards. The periotic has a large and 

 deep fossa for the flocculus on its inner side. 



sh 



I'h^th 



Fig. 54. — Hyoid bones of Frugivorous ¥>*t{Pteropus) from below, bh basihyal; 

 th thyrohyal ; sh stylohyal. 



The mandible has a high, broad, recurved coronoid pro- 

 cess, a transversely extended condyle, and flattened rounded 

 angle, without a distinct process. 



The hyoid (Fig. 54) has a narrow, transversely extended 



