Through a pocket lensNote 11 — Chapter II · ARTHROPODS AND THEIR CLASSES.—THE MARGINED WATER BEETLE; THE GREAT WATER BEETLE; THE COCKTAIL BEETLEReading editionInternational Science Series, No. lxv.◇Copy noteReturn to CHAPTER II ARTHROPODS AND THEIR CLASSES.—THE MARGINED WATER BEETLE; THE GREAT WATER BEETLE; THE COCKTAIL BEETLE