ILLUSTRATIONS. 



PAGE 



1. Balanus porcatus : an Acorn-shell, seen from top ... 2 



2. Balanus Hameri : a Sea-Acorn viewed from the side . . 3 



3. Development of Crustaceans . . . . . . 5 



4. Noctiluca ........- 10 



5. Terebella and its tube 13 



6. Sabella and its tube, showing the plume-like gills . . .16 



7. Dahlia Wartlet Anemone ( Tealia crassicornis} . . .19 



8. Joints of Lobster's Body 26 



9. Diagram of Lobster . . . . . . . 2 5 



10. Crinoid .......... 36 



11. Rosy Feather Star, and stalked young 39 



12. Cuttlefish shells 43 



13. Octopi or "Devil-fishes" 44 



14. Pearly Nautilus Shell 46 



1 5. Spirula and its shell . . . . . . . -47 



1 6. A "Sea-fir" 5 



17. Sea-fir, largely magnified, showing cups and egg-capsule . 51 



18. Development of a Sponge (Olynthus) ..... 55 



19. Starfishes .......... 67 



20. An Echinus climbing on glass of an aquarium . . -73 



21. Gall insect (Cynips kollari) 79 



22. Galls on oak-leaf : " spangles" and " button galls " . . 81 



23. Fern-frond : Woodsia ilvensis ...... 97 



24. Dandelion Down . . . . . . . .no 



25. Mistletoe ( Viscum album} flower and fruit . . . .116 



26. White Corpuscles of the Blood 127 



27. Rotifer: Male 132 



