PLATE III 



THE BRAIN AND PORTIONS OF THE VISCERAL SKELETON OF CHLAMTDOSELACHUS 

 Fig. 7- Dorsal view of the brain and cranial cavity, natural size. 



a, artery; o, nervus opticus; ocm, n. oculomotorius; ol, tractus olfactorius; tr, n. trochlearis; v, vein. 

 After AlUs, 1923, Fig. 59, pi. XXII. 



Fig. 8. Dorsal view of the branchial arches, natural size. The branchial rays related to the ceratobranchials 

 have been removed. 



bbri, second basibranchial; hbr5-6, fused fifth and sixth basibranchials; bh, basihyoid; cbl, musculus coracobranchialis 

 of the first arch; cbrl, ceratobranchial of the first arch; cbr6, ceratobranchial of the sixth arch; ch, ceratohyoid; ebrl, 

 epibranchial of the first arch; ebrd, epibranchial of the sixth arch; hbr2, hypbbranchial of the second arch; phrS, pharyngo- 

 branchial of the fifth arch. 



After Allis, 1923, Fig. 35, pi. XIII. 



Fig. 9. Ventral view of the median portion of the branchial skeleton, natural sizp. 



hbrS, basibranchial of the third arch; cbr6, ceratobranchial of the sixth arch; ch, ceratohyoid; hbr2, hypobranchial 

 the second arch. 



After Allis, 1923, Fig. 36, pi. XIII. 



