LIST OF ILLUSTRATIONS. 



FIG. PAGE 



1. A Diagrammatic Section of the 



Human Body taken vertically 

 through the Median Plane . 3 



2. A Poulpe Cuttle-fish (Octopus) 6 



3. A Centipede, or Hundred-legs 



(Scoiopendra] 6 



4. An Ascidian, or Sea-squirt (As- 



cidia) 7 



5. A Star-fish (U raster) . ... 7 



6. A Tubularian Polyp (Bimeria) 7 



7. A Foraminifer (Globigerina') . 8 



8. One of the lowest Protozoa 



(Protom&ba] 8 



9 The Lancelet (Amphioxus) . 9 



10. The Flying-Lemur (Galeopithe- 



cus) 10 



11. A Star-fish ( Uraster} . 10 



12. A Centipede, or Hundred-legs 



(Scolopeiidra) 11 



13. The Lancelet (Amphioxus). . 12 



14. A Long-armed Ape, or Gibbon 



(Hylobates) 15 



1 5 . A Lemuroid of the genus Lemur j 5 



16. The Aye-aye (Cheiromys) . . 15 



17. A Leaping Shrew (Macrosce- 



lides) 16 



18. The Flying-Lemur (Galeopithe- 



cus\ 16 



19. The Hyrax 17 



20. The Three-toed Sloth (Brady- 



pus} .......... 17 



21. The Great Ant eater (Myrme- 



cophaga) 17 



22. The Cape Ant-eater (Orycte- 



ropus) 17 



23. An Armadillo (Dasypiis] ... 17 



24. The Duck-billed Platypus(C>r/- 



tliorhynchiis) 18 



25. The Oolitic Fossil Bird (Archce- 



opteryx) 18 



26. The Frilled Lizard (Chlamydo- 



saurus~) 18 



27. An Ichthyosaurus 19 



28. A Plesiosaurus 19 



FIG. PAGE 



29. The great North American Eft, 



with per.-istent gills (Meno- 

 branchus~) 15 



30. The Hammer-headed Shark 



^(Zyg&na) 20 



31. The Eagle Ray (Myliobatis) . 20 



32. The Mud-fish (Lepidosireu) . 20 



33. Polypterus 20 



34. A Frog-fish (Chironectes) . . 20 



35. The Lamprey (Petromyzori) . 21 



36. The Lancelet (Amphioxus) . 21 



37. Articulation of a large Spine, by 



shackle-joint, with a bony 

 plate (placed below) of the 

 skin of a Siluroid Fish ... 24 



38. Axial Skeleton of the Trunk, 



with the ribs of the right side 

 removed 25 



39. A Dorsal Vertebra 27 



40. A Cervical Vertebra . . . .28 



41. The Axis Vertebra . . . . 29 



42. The Atlas Vertebra . . . .30 



43. A Lumbar Vertebra . . . .31 



44. Front and Back Aspects of the 



Sacrum 32 



45. The Coccyx 33 



46. Right Side of the Thorax . . 34 



47. Diagram of the Development 



of the Trunk and its Skele- 

 ton 3 6 



48. Axial Longitudinal Section of 



the Vertebral Column of an 

 Elasmobranch (Raia) ... 38 



49. Lateral View of four Trunk- 



Vertebra? of Siren . . . .40 



50. Upper Surface of Twelfth Cau- 



dal Vertebra of Leopard . . 40 



51. Dorsal View of Sixth, Seventh, 



and Eighth Post-sacral Verte- 

 brae of the Axolotl . . . .41 



52. Six Trunk- Vertebrae of Polyp- 



terus 4 1 



53. Seven Trunk- Vertebras of the 



Potto 4 1 



