388 



ANATOMY OF VERTEBRATES. 



are entire. In Pteropus the palatal processes of the maxillary, 21, 

 show a long fissure : those of the premaxillaries, ib. 22, are divided 

 252 t>y ^ triangular ' fora- 



men incisivum.' The 

 mandible has a broad 

 and high coronoid pro- 

 cess : the angle is 

 rounded. In Galeopi- 

 tliecus the coronoid is 

 small. 



In the cranial cavity 

 the rhinencephalic fossa 

 is large and well de- 

 fined. The petrosal 

 shows a deep cerebel- 

 lar fossa, overarched by 

 the vertical semicircular 

 Base. Mandible. caual. Thc ^ sclla ' lias 



Skull Of Pteropus. ^^ ^^.^^^-^l prOCCSSCS. 



In most insectivorous Bats the occipital condyles are sub- 

 terminal, the superoccipital, fig. 254, 3, sloping backward, and 



contributing to the crista 

 continued forward by 

 the interparietal and 

 parietal bones. The oc- 

 cipital foramen is very 

 large. The mastoid, 8, 

 is large and distinct, 

 giving attachment to the 

 tympanic, 28. Thebasi- 

 sphenoid is broad and 

 flat as in Pterojms, fig. 

 252, 5. The frontal has 

 no postorbital process. 

 The zygomatic parts of 

 the squamosal, 27, and 

 malar, 26, are slender. 

 The premaxillaries are 

 very small : in some Bats 

 they are wanting (^Rhi- 

 nolophus), or are repre- 

 sented by separate moie- 

 ties attached to the fore-part of the maxillaries. The mandible 



253 



Skull of Galeopitliecus. 



