135. 1. _Teredo navalis._ 2. _Teredo norvegica_ 202 136. _Gastrochæna modiolina_ 203 137. 1. _Thracia phaseolina._ 2. _Thracia pubescens_, SHOWING PALLIALLINE 204 138. 1. _Mya truncata._ 2. INTERIOR OF SHELL. 3. _Mya arenaria._4. _Corbula nucleus_ 205 139. _Solen siliqua_ 206 140. 1. _Solen ensis._ 2. _Cerati-solen legumen._ 3. _Solecurtus candidus_ 207 141. _Tellinidæ_ 208 142. 1. _Lutraria elliptica._ 2. PART OF THE HINGE OF _Lutraria_, SHOWING THE CARTILAGE PIT. 3. _Macra stultorum._ 4. INTERIOR OF SAME SHOWING PALLIAL LINE 210 143. _Veneridæ_ 211 144. _Cyprinidæ_ 213 145. _Galeomma Turtoni_ 214 146. 1. _Cardium pygmæum._ 2. _Cardium fasciatum._ 3. _Cardium rusticum_ 215 147. _Cardium aculeatum_ 215 148. _Pectunculus glycimeris_, WITH PORTION OF VALVE SHOWING TEETH, AND _Arca tetragona_ 216 149. _Mytilus edulis_ 217 150. 1. _Modiola modiolus._ 2. _Modiola tulipa._ 3. _Crenella discors_ 218 151. _Dreissena polymorpha_ 219 152. _Avicula_, AND _Pinna pectinata_ 220 153. 1. _Anomia ephippium._ 2. _Pecten tigris._ 3. _Pecten_, ANIMAL IN SHELL 222 154. _Terebratulina._ THE UPPER FIGURE REPRESENTS THE INTERIOR OF THE DORSAL VALVE 224 155. UNDER SIDE OF THE SHELL OF _Natica catena_, SHOWING THE UMBILICUS; AND OUTLINE OF THE SHELL, SHOWING THE RIGHT-HANDED SPIRAL 225 156. SECTION OF THE SHELL OF THE WHELK, SHOWING THE COLUMELLA 226 157. DIAGRAM OF THE ANATOMY OF THE WHELK, THE SHELL BEING REMOVED 228 158. A PORTION OF THE LINGUAL RIBBON OF THE WHELK, MAGNIFIED; AND A SINGLE ROW OF TEETH ON A MUCH LARGER SCALE 229 159. EGG CASES OF THE WHELK 230 160. PTEROPODS 231 161. NUDIBRANCHS 234 162. " 235