JAWS 



97 



A. 



cr e> pop. 



/ ,' ' 



cr. 



ink. 



FIG. 50. 



Diagrams of, A and D, an amphistylic skull (Ileptuiidi *), B and E, an autostylic skull (Euna), 

 and C and F, a hyostylic skull (Seym-urn). A, B, and C, left-side views. D, E, and F from 

 behind (the niandibular arch being dotted, and the cranium shaded), c, columella auris ; ch, 

 ceratohyal ; er, cranium ; e, junction of ethmoid and palatine cartilages ; e.p, ethmoid process ; 

 h, hyomandibular branch of facial nerve ; h.a, hyoid arch ; hm, hyomandibular ; I, labial ; mk, 

 Meckel's cartilage ; nn, nasal capsule ; o.o, junction of otic process of quadrate with the auditory 

 capsule ; o.p, otic process ; pd, palato-basai process ; pi, palatine region ; p.n, palatine brancli of 

 facial nerve ; po, preorbital process ; po.p, postorbital process ; pt, palato-quadrate cartilage ; q, 

 quadrate region ; r, rostral process ; up, spiracle ; t, tympanum. 



