MARINE UNIVALVES _Acmaea persona_ Esch. Mask Limpet. Fig. 46. _Acmaea spectrum_ Nutt. Ribbed Limpet. Fig. 47. _Acmaea patina_ Esch. Pale Limpet. Fig. 48. _Acmaea scabra_ Roe. Tile Limpet. Fig. 49. _Acmaea incessa_ Hds. Seaweed Limpet. Fig. 50. _Acmaea asmi_ Midd. Black Limpet. Fig. 51. _Acmaea (Lottia) gigantea._ Owl Limpet. Fig. 52. _Acmaea paleacea_ Gld. Chalf Limpet. Fig. 53. _Tylodina fungina_ Gab. Fig. 54. _Gadinia reticulata_ Sby. Netted Button-shell. Fig. 55. _Crucibulum spinosum_ Sby. Cup and Saucer Limpet. Fig. 56. _Crepidula dorsata_ Brod. Wrinkled Slipper-shell. Fig. 57. _Crepidula aculeata_ Gmel. Prickly Slipper-shell. Fig. 58. _Crepidula adunca_ Sby. Hooked Slipper-shell. Fig. 59. _Crepidula nivea_ Gould. White Slipper-shell. Fig. 60. _Crepidula onyx_ Sby. Onyx Slipper-shell. Pl. II. Fig. 19. _Fissurella volcano_ Rve. Volcano Shell. Fig. 62. _Fissuridea aspera_ Esch. Rough Key-hole Limpet. Fig. 63. _Fissuridea murina_ Dall. White Key-hole Limpet. Fig. 64. _Lucapina crenulata_ Sby. Great Key-hole Limpet. Fig. 65. _Clypidella (Lucapinella) calliomarginata_ Cpr. Southern Key-hole Limpet. Fig. 66. _Megatebennus bimaculatus_ Dall. Spotted Key-hole Limpet. Fig. 67. _Turris (Bathytoma) carpenteriana_ Gab. Carpenter Turret Shell. Fig. 68. (Laguna Beach, Jahraus.) _Trophon belcheri_ Hds. Belcher Trophon. Fig. 69. (Jahraus.) _Trophon triangulatus_ Cpr. Three-cornered Trophon. Dredged off Laguna Beach. Bean. Fig. 70. _Australium undosus_ Wood. Wavy Topshell. Fig. 71. _Bullaria gouldiana_ Pisb. Gold's Bubble-shell. Many collected at Balboa much larger than the specimens shown. Fig. 72. _Haminea vesicula_ Gld. White Bubble-shell. Fig. 73. _Haminea virescens_ Sby. Green Bubble-shell. Fig. 74. _Cypraea spadicea_ Gray. Nut-brown Cowry. Fig. 75. _Trivia californica_ Gray. Little Coffee-bean. Fig. 76. _Trivia solandri_ Gray. Solander Trivia. Fig. 77. _Erato vitellina_ Hds. Veally Erato. Fig. 78. (Slightly enlarged.) _Erato collumbella_ Mke. Dove Shell. Fig. 79. _Marginella varia_ Sby. Colored Marginella. Fig. 80. _Marginella jewetti._ California Rice shell. Much like the last but white. _Olivella biplicata_ Sby. Purple Olive Shell. Fig. 81. _Olivella pedroana_ Conr. Pedro Olive Shell. Fig. 82. _Conus californicus_ Hds. California Cone. Fig. 83. _Macron lividus_ A. Ad. Livid Macron. Fig. 84. _Littorina scutulata_ Gld. Checkered Littorine. Fig. 85. _Littorina planoxis_ Nutt. Gray Littorine. Fig. 86. Turned. _Purpura (Cerostoma) nuttallii_ Conr. Nuttall's Hornmouth. Fig. 87. _Tegula (Chlorostoma) gallina_ Fbs. Speckled Turban Shell. Fig. 88. _Tegula (Chlorostoma) aureotincta_ Fbs. Gilded Turban Shell. Large umbilicus with yellow. Fig. 89. _Omphalus fuscecens_ Phil. Banded Turban Shell. Fig. 90. _Tegula veridula ligulata_ Wke. Fig. 91. _Norrisia norrisii_ Sby. Smooth Turban Shell. Fig. 92. _Thais emarginata_ Desh. Rock Purple. Fig. 93. _Acanthia lapilloides_ Conr. Pebbly Unicorn. Fig. 94.