xvi LIST OF WOODCUTS. 



PAGE 



HO. 



25. Diagram showing the Intervertebral Remains of the Notochord 36 



26. Portion of the Vertebral Column of Lepulostnts. (After Balfour and 



Parker.) 37 



27. Portion of the Vertebral Column of a Young Dogfish (Scyllium canicula). 



(After Cartier.) 38 



28. Portion of the Vertebral Column of ticymnus '. . 38 



29. Tail of Protopterus 39 



30. Tail of Lcpidosteus 39 



31. Longitudinal Section through the Vertebral Column of Various Urodeles. 



A, Ranodon sibericus; B, Amblystoma tigrinum ; C, Gyrinophilus por- 



phyriticus ; D, Salamandrina perspicillata 40 



32. Vertebral Column of Discoglossus pictus 41 



33. Tail of Archceopteryx 44 



34. Pelvis of Owl (Strix bubo). (Ventral view.) 45 



35. Third Cervical Vertebra of "Woodpecker (Pints viridis). (Viewed 



anteriorly.) 46 



36. Skeleton of the Trunk of a Falcon 49 



37. Costal Arch of Man 50 



38. Ventral Portion of the Pectoral Arch of Rana esculenta 52 



39. Pectoral Arch and Sternum of a Gecko (Hemidactylus verrucosus) .... 52 



40. A, Sternum of Fox ; B, of Walrus ; and C, of Man 53 



41. Diagram showing the Primitive Metameric Condition of the Head .... 55 



42. First Cartilaginous Rudiments of the Skull 57 



43. Diagrammatic Transverse Sections, of the Head in Embryo (A) Sturgeons, 



Elasmobranchs, Anura, and Mammals ; (B) Urodeles and Snakes ; and 



(C) Certain Teleosteans, Lizards, Crocodiles, Chelonians, and Birds . . 58 



44. Second Stage in the Development of the Primordial Skull 58 



45. Diagrammatic Transverse Section of the Third Stage in the Development 



of the Primordial Skull 59 



46. Diagram showing the Relations of the Embryonic Visceral Skeleton ... 60 



47. Semidiagrammatic Figure of an Elasmobranch Skull, showing the Relations 



of the Segmental Cranial Nerves 60 



48. Semidiagrammatic Figures of the Suspensorial Apparatus in Various Verte- 



brates. (Mainly after Gegenbaur.) A, Notidanus ; B, Other Elasmo- 

 branchs ; C, Torpedo ; D, Teleosteans ; E Amphibians, Reptiles, and 



Birds ; F, Mammals 61 



49. Skull and Branchial Basket of Petromyzon planen 64 



50. Skull of Heptanchus 64 



51. Cranial Skeleton of Raja oxyrhyncha 65 



52. Cranial Skeleton of Sturgeon (Acipenser) after Removal of the Exoskeletal 



Parts 66 



53. Skull of Polyptcrus bichir from the Dorsal Side 67 



54. Cranial Skeleton, Pectoral Arch, and Anterior Extremity of Protoptenis . . 68 



55. Cranial Skeleton of Trout 69 



56. Skull of Young Axolotl. (Ventral view.) . . 71 



57. Skull of Salamandra atra (Adult). (Dorsal view.) 71 



