x ILLUSTKATIONS 



FIG. PAGE 



33. ANODONTA. DIAGRAM OF CIRCULATORY SYSTEM . . 69 



34. ANODONTA. SECTION OF GILL . . . . * 70 



35. ANODONTA. GLOCHIDIUM LARVA 71 



36. DEVELOPMENT OF TROCHOPHORE LARVA OF A BIVALVE 



MOLLUSC . . . . . 73 



37. LUMBRICUS. LONGITUDINAL SECTION OF ANTERIOR END 79 



38. LUMBRICUS. SECTION OF INTESTINAL EEGION . . 80 



39. LUMBRICUS. DIAGRAM OF NEPHRIDIUM . . . 83 



40. LUMBRICUS. DIAGRAM OF EEPRODUCTIVE ORGANS . 85 



41. LUMBRICUS. PAIRING . . . . . . 85 



42. LUMBRICUS. DEVELOPMENT ... . .87 



43. NEREIS. ANTERIOR END . . . . , . 88 



44. NEREIS. TRANSVERSE SECTION . . .... . .88 



45. TROCHOPHORE LARVA OF A POLYCHAET . . . 89 



46. NEPHROPS. EXTERNAL CHARACTERS 95 



47. NEPHROPS. GILLS . . .... .99 



48. NEPHROPS. LONGITUDINAL SECTION . . .101 



49. NEPHROPS. GASTRIC MILL, HEART, AND GREEN GLAND 102 



50. NEPHROPS. TRANSVERSE SECTION . . . . 105 



51. NEPHROPS. AN OMMATIDIUM OF THE EYE AND THE 



NERVOUS SYSTEM . . . . . . . 107 



52. NEPHROPS. EEPRODUCTIVE ORGANS .... 109 



53. CARCINUS. ATTACHMENT OF EGGS TO SETAE OF ABDO- 



MINAL APPENDAGES 110 



54. NEPHROPS. LARVA Ill 



55. BLATTA. MALE AND FEMALE . . . . . 115 



56. BLATTA. MOUTH APPENDAGES . . . . 116 



57. BLATTA. MOUTH APPENDAGES . . . . .- 117 



58. BLATTA. DIAGRAM ILLUSTRATING THE GENERAL STRUC- 



TURE . ... . . . . ; 119 



59. DIAGRAM TO ILLUSTRATE THE LIFE-HISTORIES OF 



ANOPHELINE AND CULICINE MOSQUITOES . .125 



60. ANOPHELES. HEAD APPENDAGES OF FEMALE . . 127 



61. AMPHIOXUS. THE ADULT FROM THE LEFT SIDE . . 133 



62. AMPHIOXUS. THE ANTERIOR END OF A YOUNG SPECIMEN 136 



63. AMPHIOXUS. TRANSVERSE SECTION OF PHARYNX . 137 



64. AMPHIOXUS. DIAGRAMMATIC TRANSVERSE SECTION OF 



ABDOMINAL EEGION . . . r -.-: 138 



65. AMPHIOXUS. DIAGRAM OF BLOOD CIRCULATORY SYSTEM 139 



66. AMPHIOXUS. BRAIN VESICLE 140 



67. AMPHIOXUS. PROTONEPHRIDIUM .... 142 



68. AMPHIOXUS. SEGMENTATION OF EGG . . . ,143 



69. AMPHIOXUS. GASTRULATION . . . _.. ... .--.>. 144 



70. AMPHIOXUS. LATERAL VIEWS OF EMBRYOS . .145 



71. AMPHIOXUS. TRANSVERSE SECTIONS OF EMBRYOS . 147 



72. AMPHIOXUS. TRANSVERSE SECTIONS OF LARVAE . 148 



73. AMPHIOXUS. HEAD OF LARVA 149 



