LIST OF ILLUSTRATIONS. 



FIG. PAGE 



1 Diagrammatic sections of various forms of teeth ... 6 



2 Cervical vertebrae of an Ox (Bos taurus) .... 15 



3 Diagram of the skeleton of Amphioxus lanceolatus . . 51 



4 Dorsal, lateral, and ventral views of the skull of Petro- 



myzon marinus 56 



5 Skull of a male Chimaera monstrosa 65 



6 Lateral view of the skull of a Dogfish (Scyllium canicula) . 75 



7 Semidorsal view of the pectoral girdle and fins of a Dogfish 



(Scyllium canicula) . 80 



8 Dorsal view of the pelvic girdle and fins of a male Dogfish 



(Scyllium canicula) 81 



9 Dorsal and ventral views of the cranium of a Salmon (Salmo 



salar) from which most of the membrane bones have been 



removed 88 



10 Lateral view of the chondrocranium of a Salmon (Salvio 



salar) 90 



11 Lateral view of the skull of a Salmon (Salmo salar) . . 92 



12 Mandibular and hyoid arches of a Cod (Gadus morrhua) . 99 



13 Eight half of the pectoral girdle and right pectoral fin of a Cod 



(Gadus morrhua) 102 



14 Diagram of a section through the jaw of a Shark (Odontaspis 



americanus) showing the succession of teeth . . . 107 



15 Part of the lower jaw of a Shark (Galeus) .... 108 



16 Skulls of Notidanus and Cestracion ..... 118 



17 Dorsal view of the branchial arches of Heptanchus . . 120 



18 Lateral view of the skull of a Sturgeon (Acipenser sturio) . 122 



19 Dorsal and ventral views of the cranium of Ceratodus miolepis 125 



20 Lateral view of the skeleton of Ceratodus miolepis . . 128 



21 Dorsal, ventral and lateral views of the skull of a Newt (Molge 



cristata) 142 



22 Ventral and lateral views of the shoulder-girdle and sternum 



of an old male Crested Newt (Molge cristata) . . . 146 



