xviii LIST OF ILLUSTRATIONS 



FIG. PAGE 



30. Bones of arm with biceps muscle . ... . . -67 



31. Viscera of male frog 69 



32. Hydra 73 



33. Sycon ciliatum 76 



34. Sycon gelatinosum 77 



35. Sycon gelatinosum, magnified 78 



36. Sycon gelatinosum, transverse section 80 



37. Ascetta primordialis .84 



38. Section of Spongilla 85 



39. Skeleton of sponges 87 



40. Sponge spicules 88 



41. Obelia colony 93 



42. Nematocysts of Hydra 96 



43. Dissection of Medusa . . 97 



44. Development of Laomedea and Eudendrium ... 99 



45. Structure of Hydra 100 



46. Petasus and Glossocodon . 102 



47. Bougainvillea ramosa ........ 103 



48. Physaiia 106 



49. Physaiia arethusa 106 



50. Halistemma tergestinum 107 



51. Aurelia aurita, partly dissected 109 



52. Aurelia aurita, development in 



53. Tessera princeps 113 



54. Tealia crassicornis 115 



55. Sea-anemone, in sections 116 



56. Common sea-anemone 118 



57. Corallium rubrum 118 



58. Alcyonium palmatum 119 



59. Tubipora musica 120 



60. Pennatula sulcata 121 



61. Flabellum curvatum 122 



62. Astraea pallida 123 



63. Dendrophyllia nigrescens and Madrepora aspera . . .124 



64. Cancrisocia on back of a crab . . . . . .125 



65. Hormiphora plumosa . . . . . . . .126 



66. Hormiphora plumosa, section of a tentacle . . . .127 



67. Idyia roseola 128 



