PLATE II 



THE CRANIUM AND PORTIONS OF THE VISCERAL SKELETON 

 OF CHLAMTDOSELACHUS 



Fig. 4. Medial view of cranium and anterior end of the vertebral column, natural size. 



an, ala nasalis; bd, basidorsals; ef, endolymphatic fossa; fe, foramen for efferent pseudobranchial artery; /gl, foramen for 

 nervus glossopharyngeus; fie, foramen for internal carotid artery; fo, foramen for nervus opticus; foe, foramina for 

 occipital nerves; fol, foramen for nervus olfactorius; fom, foramen for nervus oculomotorius; ftr, foramen for nervus 

 trochlearis; fv, foramen for nervus vagus; id, interdorsal; nc, notochord; pb, palatobasal ridge; pv, canal, or foramen, for 

 pituitary vein; r, rostrum; tf, acustico-trigemino-facialis recess. 



After Allis, 1923, Fig. 12, pi. IX. 



Fig. 5. Lateral view of cranium, with jaw cartilages and hyoid cartilages attached, natural size. 



al, anterior upper labial cartilage; an, ala nasalis; aop, antorbital process; ch, ceratohyoid; ecp, ectethmoidal process; 

 es, eyestalk; g( = gamma), the process corresponding to Addy of Vetter's (1874) description in other selachians; hmd, 

 hyomandibular; Imh, hgamentum mandibulo-hyoideum; md, mandibular; ml mandibular labial cartilage; n, nodule of 

 cartilage; naf, nasal fontanelle; orp, orbital process of palatoquadrate; pi, posterior upper labial cartilage; pop, postot' 

 bital process; pq, palatoquadrate. 



After Allis, 1923, Fig. 7, pi. VII. 



Fig. 6. Posterior view of the cranium, natural size. 



af, articular facet for hyomandibular; ecp, ectethmoidal process; es, eyestalk; fm, foramen magnum; gvf, glossopharyngo- 

 vagus fossa; pop, postorbital process. 



After AlUs, 1923, Fig. 10, pi. VIII. 



