INDEX, 



39^ 



Opisoma, Stolioz. . Ill 



Opistliobrauchiata, II 



II 



Opisthophorus, Bens. II 



Opisthoptera, Meek. Ill 



Opisthostoma, Blanf. II 



Oppelia, Waagen. . II 



Optediceras, Leith. II 



Orbicella, d'Orb. . Ill 



Orbicula, Cuvier. . Ill 



Orbicula, Sowb. . Ill 



Orbicnlarius, Dumer. Ill 



Orbiculoidea, d'Orb. Ill 



Orbicitlus, Megerle. Ill 



Orbis, Lea. ... II 



Orbis, Scliroter, . Ill 



Orbitina, Risso. . Ill 



Orbulites, Lam. . . II 



Orcula, Held. . . Ill 



Orina, A. Ad. . . II 



Oriostoma, M.-C. . II 



Ormoceras, Stokes. II 



Ornithopus, Gardner. II 



Orodoris, Bergh. . II 



Orphnus, Albers. . Ill 



Orpiella, Glray. . . Ill 



Orthalicidse. . . . Ill 



Orthalicinus, C. & F. Ill 



Orthalicus, Beck. . Ill 



Orthambonites, Pan. Ill 



Orthaulax, Grabb. . II 



Orthis, Dalman. . Ill 



Orthisina, d'Orb. . Ill 



Orthoceras, Breynius. II 

 u u III 



Orthoceratites,Breyn. II 

 Orthodesma, H. & W. Ill 

 Orthodonta. . . . Ill 

 ... Ill 

 Orthodontiscus, Mk. Ill 

 Orthonema, M. & W. II 

 Ortbonota, Conrad. Ill 

 Ortbonychia, Hall. II 

 Orthopoma, Gray, . II 

 Ortliostelis, Arad. , II 

 Orthostoma, Desh. . II 



PAGE 



230 



99 



351 



288 



275 



283 



78 



272 



340 



334 



337 



334 



338 



180 



220 



106 



61 



80 



70 



230 



208 



'52 



196 



371 



48 



26 



58 



59 



58 



328 



192 



328 



329 



51 



347 



51 



155 



345 



349 



235 



234 



154 



214 



298 



234 



355 



Orthost^dus, Beck. . Ill 



Orthotetes, Fischer. Ill 



Orthothrix, Geiuitz. Ill 



Orthotoma, Quenst. Ill 

 Orthotomium, C. & F. Ill 



Orustia, Morcb. , III 



Orygoceras, Brusina. II 



Oscanius, Gray. . . II 



Oscilla, A. Ad. . . II 



Osilinus, Phil. . . II 



Ostomya, Conrad. . Ill 



Ostrea, Linn. . . Ill 



Ostreidffi Ill 



Ostreuomia, Conrad. Ill 



Otala, Morch. . . Ill 



Otala, M.-T. . . . Ill 

 Otala, Schum. , . 

 Otavia, Gray. 

 Otesia, H. & A, Ad. 



Othelosoma, Gray. 

 Otina, Gray. . . 

 Otinidae. ... 

 Otoceras, Griesb. 

 Otocheilus, Conr. 

 Otopoma, Gray. 

 Otostoma, d'Arch. 

 Otostomus, Beck. 

 Otns, Risso. . . 

 Ovatella, M.-T. . 

 Ovella, Pfeiffer. . 

 Ovulum, Bruguiere 

 Owenia, Prosch. 

 Oxycheilus, Albers 

 Oxychilus, Fitzinger. Ill 

 III 

 Oxychona, Morch. Ill 

 Oxygnatha. . . . Ill 

 Oxygyrus, Benson. II 

 Ox3aioe, Raf. . . II 

 Oxynoticeras, H3^att. II 

 Oxyperas, Mch. . Ill 

 Ox^'Stele, Philippi. II 

 Oxytes, Pfeiffer. . Ill 

 Oxj^oma, Meek. . Ill 

 Ozsena, Rafinesque. II 



III 



II 



III 



III 



III 



III 



III 



II 



II 



II 



II 



III 



II 



III 



III 



II 



II 



III 



PAGE 



47 



328 



333 



309 



52 



47 



289 



366 



237 



313 



153 



297 



296 



295 



35 



42 



45 



314 



22 



27 



72 



185 



285 



294 



52 



203 



94 



49 



199 



29 



51 



23 



37 



36 



19 



351 



362 



73 



157 



314 



26 



271 



20 



