Galeodes, a spider-like animal, 85, 86. Gasteropoda, 29, 98-107. Gasteropoda, classification of, 29. Gastræa, 40. Gastrula, larva, 41, 150. Genus, 32. Gills, 45, 141, 149. Grades, 34, 35-38. Gregarina, 49. H. Heliozoa, 48. Hemichordata (or Adelochorda), 33, 43, 145. Hermit Crabs, 80. Holostomata, 105. Hybrid, 32. Hydra, 36, 41, 54, 59. I. Infusoria 10, 47. "Infusorial earth," 47. Insects, true, 88-97. J. Jelly-fish, 57, 58. K. Kangaroo, 163. L. Lamellibranchiata, 107. Lamp-shells, 119. Land Animals, 166. Larvæ, larval forms, 40, 41. Larvæ of Brachiopods, 119. Larvæ of Insects, 90. Larvæ of Molluscs, 115. Lancelet (Amphioxus), 41, 140, 149. Leeches, 71. Limpet, Common, 17, 19, 20, 29, 30. Limpet, Semi-transparent, 15-20. Liver-fluke, 71. Lobsters, 80. Lophophore, 117, 122. Lustre, metallic, of feathers, 157. M. Mammalia, 160. Man, 13, 26, 167-180. Mantle (of bivalve molluscs), 108. Marsupialia (or Metatheria), 161. Marsupium or nursery-pocket, 161. Mesoblast, 38. Mesoderm or middle body-layer, 37, 61. Metameric symmetry, 70. Mesozoa, 35. Metazoa, 35. Microscope, 9, 10, 182. Microscope, Sections for the, 182. Microtome, 185. Mites, 87. Mollusca, 29. Mollusca (classification of Gasteropod), 29. Moths, 93. Monoblastic, 34. Moss-Corals, 33, 39, 119. Mule, 32. Mussel, Common, 103. N. Nematodes, 71. Notochord, 135, 139, 145, 149, 151. Nucleus, 35. Nummulite, 46. O. Odontophore, 100. Operculum (of univalve molluscs), 105. Opossum, 161. Orders, 33. Orthonectidae, 34. P. Pelecypoda, 107. Perforating gills (of vertebrates and other chordata), 142, 144. Peripatus, 88. Periwinkle, Common or Edible, 19, 26, 105. Periwinkle, High-tide-mark (_L. rudis_) 19, 105, 114. Periwinkle, Yellow, 19, 21, 23, 25, 30, 105. "Persons" of a colony, 58. Phoronis, 122. Phylum, pl. phyla, 33. Placophora, 113. Planarian Worms, 37, 70. Planula Larva, 41. Platyhelminthes, 44, 71. Polycystina, 47. Polyzoa, 119. Porifera, 33, 63, 68. Protective Coloration, 15, 25. Protophyta, 50. Protoplasm, 35. Prototheria, 161. Protozoa, 33, 44, 45. Pseudopodia, 36. R. Radial Symmetry, 53. Radiata, 53. Radiolarians, 47. Rainbow Worm, 72, 159. Reptiles, 154-156. Rhabdopleura, 145. Rhizopoda, 36, 46, 48. Rodent, Teeth of, 163. Rotifers, 76. S.