X TABLE OF CONTENTS. 



PAGE 



LAMELLIBRANCHIATA. 



24. Shell of Fresh-water Mussel, Anodonta cygnea . . . . 124 



25. General external features of same . . . . . . . 128 



26. Viscera in situ of same . . . . . . . .132 



27. Nervous system of same . . . , , ' . 135 



INSECTA. 



28. Common Cockroach, Periplaneta orientalis . . . . .138 



29. Larva of Privet Hawk Moth, Sphinx Ligustri -.' ''* . . 147 



30. Pupa of same . . . ...... . . 152 



31. Imago, male and female, of same . ..... ... . . 156 



CRUSTACEA. 



32. Common Crayfish, Astacus fluvia tills, female . . . . 162 



33. The same bisected, male . . . . . . .. 177 



34. Heart and vessels of same . . . . . ..179 



35. Digestive, reproductive, and respiratory organs of same . . .. 181 



36. Nervous system of same . . . . . . .-- 187 



ASTEROIDEA. 



37. Common Starfish, Asterias rubens, dried . . .'- . . 190 



38. Digestive and motor organs of same . . , . r - .. 195 



CHAETOPODA. 



39. Common Earthworm, Liimbricus terrestris , . , 196 



40. Digestive, reproductive, and circulatory organs of same . . . 201 



41. Nervous system of same . . * '. * . 209 



HIRUDINEA. 



42. Medicinal Leech, Hirudo medidnalis , , . . . . 212 



43. Digestive organs of same . . . ' . . .216 



44. Nervous system of same .. . . . . . . 219 



45. Reproductive and excretory organs of same . . . . 221 



CESTODA. 



46. Tapeworm, Taenia serrata, and cysts of Cysticercus pisiformis . 224 



47. Cysticercus pisiformis, mounted for microscope . ., . . 229 



POLYZOA. 



48. Broad-leafed Hornwrack, Flustra foliacea . . . . . 234 



ANTHOZOA. 



49. Sea Anemone, Tealia crassicornis . . , , . : , ' . 239 



HYDROZOA. 



50. Sea-Fir, Sertularia abietina ; Medusa . . . . 245 



PORIFERA. 



51. Fresh-water Sponge, Spongilla lacustris Euspongia officinalis . 249 



INFUSORIA AND AMOEBINA. 



52. Infusorian, Paramecium Aurelia and Amoeba Proteus . . . r 254 



