50. Xylophaga dorsalis. Xylotrya, Leach. 51. The same, in wood. (This would be more properly placed in Pholadaria.) 52. Gastrochæna Modiolina, in the tube (from Sowerby's Genera.) 53. Fistulana Clava. } } (From Sowerby's Genera.) 54. Tube of the same. } _Fam._ Pholadaria. 55. Pholas Dactylus; _a_, plates of the hinge. 56. ---- papyracea. Pholadidæa. 57. Pholadomya Candida. 58. Galeomma Turtoni. 59. Front view of the same. (Here Xylophaga should be placed, see Tubicolaria.) _Fam._ Solenacea. 60. Solen ensis. Ensis, Schum. Ensatella, Sw. 61. Solen radiatus. Solenocurtus, Bl. Leguminaria, Schum. Siliqua, Megerle. 62. Lepton squamosum. (from Turton.) 63. Novaculina gangetica. 64. Glanconome Chinensis. 65. Panopæa Australis. } } (From Sowerby's Genera.) 66. Hinge of Panopæa Faujasii.} 67. Glycimeris Siliqua. 68. Solenimya Mediterranea. _Fam._ Myaria. 69. Anatina rostrata. Auriscalpium, Megerle. 70. Anatinella Sibbaldii. 71. Mya truncata. 72. Periploma inæquivalvis. Osteodesma, Desh. _a_, bone of the hinge, (from Blainville.) 73. Myochama anomioides; lower valve with clavicle, and hinge of upper valve. 74. External view of the same, attached to a Trigonia. 75. Cleidothærus Chamoides, attached valve. 76. Upper valve of the same, with the clavicle. _Fam._ Mactracea. 77. Lutraria papyracea. Ligula, Leach. Carinella, Adans. 78. ---- Solenoides. Cutellus ----? 79. Mactra Stultorum. 80. ---- plicataria. Spisula? Gray. 81. ---- Spengleri. Schizodesma, Gray. 82. ---- bicolor. Mulinia, Gray. 83. Gnathodon cuneatus. Clathodon, Conrad. 84. Crassatella rostrata. 85. Amphidesma reticulatum. 86. Erycina plebeja. Mesodesma, Desh. 87. Cuming mutica. 88. Ungulina transversa, (from Sowerby's genera.) _Fam._ Corbulacea. 89. Corbula nucleus. 90. Pandora rostrata. _Fam._ Lithophagidæ. 91. Petricola Roccellaria. 92. ---- Carditoidea. Coralliophaga, Bl. 93. Thracia corbuloides. 94. Saxicava rugosa. 95. Hiatella biaperta. 96. Sphænia Binghamii. 97. Venerirupis vulgaris. _Fam._ Nymphacea. 98. Sanguinolaria rosea. Lobaria, Schum. 99. ---- Diphos. Soletellina, Bl. 100. Psammobia Ferroensis. Gari, Schum. 101. Corbis fimbriata. Fimbria, Megerle. 102. Grateloupia Moulinsii. (from Lea.) 103. Egeria triangulata, (from Lea.) 104. Lucina tigerina. 105. Tellina radiata. 106. ---- lingua-felis; _a_, showing the fold in the ventral margin. 107. Tellinides rosea. 108. Donax cuneatus. 109. Capsa Braziliensis, young.