xii Illmtralions 



PAGE 



21. Gills 148 



22. Blood Systems 154 



23. Relative Sizes of Egg and Sperm in the Flounder . .157 



24. Tarpon 201 



25. Larval or Leptocephalid Stage of Bonefish . . . 203 



26. Swordfish, Young and Adult 210 



27. Sea-Horse .......... 249 



28. Male Betta Under His Bubble-Nest, Releasing Another 



Bubble 251 



29. Ray and Flounder 252 



30. Fierasfer About to Enter His Holothurian Home . . 256 



31. Trigger Fish 257 



32. Angler-Fish 258 



33. Remora , 258 



34. Female Angler with Dw^arf Parasitic Male Attached to 



Abdomen 269 



DIAGRAMS 



A-K Underwater Optics 68-78 



L-N The Fish's Visual Mechanism 86-89 



PLATES 



betw^een pages 1 80-1 81 



L Scales: Striped Bass and Trout 



IL Scale: Steelhead 



in. Changes in the Color Pattern of the Flatfish 



IV. Spawning Jewel-Fish 



Female Jewel-Fish Brooding Eggs 



V. Cutthroat Trout at Moment of Spawning 



VI. Bonneville Dam Fish Ladder 



