176 THE SKULL. [CHAP. 



and there is a large unossified space on each side of the 

 base of the skull. 



The mandible in the Insectivora has generally an elongated 

 and rather narrow horizontal portion, above which the 

 transversely extended condyle is but slightly elevated, and 

 there are well-developed coronoid and angular processes ; 

 the latter is remarkably long and slender in the Shrews. 



The hyoid is formed generally like that of the Carnivora, 

 with three complete extracranial ossifications in the anterior 

 arch, a transversely extended basihyal, and tolerably long, 

 stout, flattened thyrohyals, sometimes ankylosed with the 

 basihyal. 1 



Order CHIROPTERA. In the large Frugivorous Bats 

 (Pteropus), the cranium is generally elongated, the cerebral 

 cavity large, oval, arched above, and contracted in front : 

 its walls formed mainly by the greatly expanded parietals, 

 both supraoccipital and frontals being small. In old indi- 

 viduals of some species there are well-marked sagittal and 

 occipital crests. The base of the cranium is elongated, flat, 

 and thin. The facial part is long and rather compressed. 

 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 lacrymal 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 : 



1 For details of the osteology of the Insectivora, see G. E. Dobson's 

 valuable monograph of the group, now in course of publication. 



