I.] THE FROG. ^J 



iii. The foramen of exit for V. VI. VII. ; a large 

 aperture, below and in front of the pro-otic, 



iv. The foramen for IX. and X.; perforating the 

 body of the exoccipital. 



V. The auditory foramen (VIIL); a small per- 

 foration of the cartilaginous wall of the audi- 

 tory capsule just behind iii. 



vi. The foramen for III. ; small and situated im- 

 mediately in front of iii. 



vii. The foramen for IV. {ri. patheticus) very 

 small, above and a little in front of the optic 

 foramen. 



f. The mandible. See 4. e. p. 



Strip off the dentary with care; there will be 

 found, in close apposition with the outer face of 

 the angulo-splenial, 



a. Meckel s cartilage ; a gristly rod, forming a core 

 for the lower jaw. Examine its posterior end; 

 it is alone concerned in articulation* 



/?. The mento-Meckelian bone \ a small nodule aris- 

 ing as an ossification of the symphysial end 

 oi a. 



6. The hyoid. 



a. Its broad somewhat tetragonal central part {body), 

 bearing a number of outstanding processes, for 

 attachment of muscles (cf Sect. E. 2. c). This 

 is usually cartilaginous, being ossified only in old 

 individuals. 



b. Its posterior cornua, or thyro-hyals ; short bony 

 rods, sloping obliquely backwards and outwards. 



5—3 



