_Pleuracanthus decheni_, Restored. 520 Head-bones and Teeth of _Pleuracanthus decheni_. 520 Teeth of _Didymodus bohemicus_. 520 Shoulder-girdle and Pectoral Fins of _Cladodus neilsoni_. 521 Teeth of _Cladodus striatus_. 522 _Hexanchus griseus_, Griset or Cow-shark. 523 Teeth of _Heptranchias indicus_. 524 _Chlamydoselachus anguineus_, Frill-shark. 525 _Heterodontus francisci_, Bullhead-shark. 526 Lower Jaw of _Heterodontus philippi_. 526 Teeth of Cestraciont Sharks. 527 Egg of Port Jackson Shark, _Heterodontus philippi_. 527 Tooth of _Hybodus delabechei_. 528 Fin-spine of _Hybodus basanus_. 528 Fin-spine of _Hybodus reticulatus_. 528 Fin-spine of _Hybodus canaliculatus_. 529 Teeth of Cestraciont Sharks. 529 _Edestus vorax_, Supposed to be a Whorl of Teeth. 529 _Helicoprion bessonowi_, Teeth of. 530 Lower Jaw of _Cochliodus contortus_. 531 _Mitsukurina owstoni_, Goblin-shark. 535 _Scapanorhynchus lewisi_, Under Side of Snout. 536 Tooth of _Lamna cuspidata_. 537 _Isuropsis dekayi_, Mackerel-shark. 537 Tooth of _Isurus hastalis_. 538 _Carcharodon mega odon._ 539 _Cetorhinus maximus_, Basking-shark. 540 _Galeus zyopterus_, Soup-fin Shark. 541 _Carcharias lamia_, Cub-shark. 542 Teeth of _Corax pristodontus_. 543 _Sphyrna zygæna_, Hammer-head Shark. 544 _Squalus acanthias_, Dogfish. 545 _Etmopterus lucifer._ 546 Brain of Monkfish, _Squatina squatina_. 547 _Pristiophorus japonicus_, Saw-shark. 548 _Pristis pectinatus_, Sawfish. 550 _Rhinobatus lentiginosus_, Guitar-fish. 551 _Raja erinacea_, Common Skate. 552 _Narcine brasiliensis_, Numbfish. 553 Teeth of _Janassa linguæformis_. 554