166 



ZOOLOGY. 



tion of the skull of frog and mammal. There is no 

 parasphenoid in the dog ; and, instead, a complete series of 

 ossifications, the median basi- and pre-sphenoids, and the 

 lateral ali- and orbito-sphenoids occur ; so that, in place of 

 the largely cartilaginous skull of the frog, we have a 

 completely bony skull. The points can be rendered much 

 more luminously in a diagram than in the text, and we 

 would counsel the student to compare this of the frog very 

 carefully with that of the dog (p. 83). 



CRANIUM. 



NASALS 



VOMEES 



FRONTO- PARIETALS 

 Cartilaginous 



Side-Walls 



o 



rH 



6 



Cartilaginous 

 Roof 



E-x-occipitals 



Columellat 

 Cartilaginous Floor 

 PARASPHENOID 



UPPER JAW. 



SQUAMOSALS 



PRE-MAXILK PALATINES PTERYGOIDS Quadrate 



Cartilage 



MAXILLAE QUADRATO-JUGALS 



Afento-meckelians 



LOWER JAW. 



Meckel's Cartilage 

 DENTABIES ANQULO-SPLENIALS 



HYOID. 



