xiii.] THE FROG. 219 



outer end of the palatine, and closely applied to 

 the maxilla, is a bone, which soon separates 

 from the maxilla, and becoming broad and 

 stout, bifurcates; the inner process nearly joins 

 the para sphenoid and is moveably articulated 

 with the skull j the outer runs along the inner 

 face of a cartilage (the suspensorium\ on the 

 outer face of which the squamosal rests : this is 

 the pterygoid bone. 



At the outer edge of each vomer, immediately 

 in front of the palatine, is an aperture which 

 leads into the nasal cavity. These two apertures 

 are the posterior nares. 



4. The side of the skull. 



a. Running back from that part of the pre-maxilla 

 which bounds the gape is a long bone, forming 

 almost the whole of the rest of the upper edge 

 of the gape; this is the maxilla. 



b. Joined to the posterior end of the maxilla is a 

 small bone, which at its posterior end is attached 

 to the distal portion of the squamosal. This is 

 the quadrato-jugal. 



c. The under jaw or mandible consists of two dis- 

 tinct portions, or rami, which meet in the middle 

 line in front, and which, behind, articulate with 

 the extremities of the suspensorial cartilages. 

 In the articular end of each suspensorial cartilage 

 there is an ossification which represents the 

 quadrate bone in other Vertebrata, and is united 

 with the jugal to form the quadrato-jugal. 



In each ramus three pieces may be made out 



