TABLE OF CHARACTERISTIC GENERA. 123 
It. TABLH OF CHARACTERISTIC GENERA. 
SYSTEMS. GENERA AND SUB-GENERA. 
‘Camaroceras, Endoceras, Gonioceras, Pterotheca. 
1. CAMBRIAN, or Maclurea, Raphistoma, Holopea, Platyceras. 
Lower Silurian ..... Orthisina, Platystrophia, Porambonites, Pseudo-crania. 
Ambonychia, Modiolopsis, Lyrodesma. 
Actinoceras, Phragmoceras, Trochoceras, Ascoceras. 
EMU LAN) scicccteceses Theca, Holopella, Murchisonia, Atrypa, Retzia. 
Cardiola, Clidophorus, Goniophorus, Grammysia. 
( Bactrites, Gyroceras, Clymenia, Apioceras, Serpularia. 
3. DEVONIAN .....csce0es + Spirifera, Uncites, Merista, Davidsonia, Calceola. 
4, CARBONIFEROUS... 
ESR MOUAN . .ccccccccess 
SUPA ARSTIO.. ccccesse 
9, L. CRETACEOUS ... 
10. U. CRETACEOUS... 
PVE FIOCEINE “cacesscesecscs 
TO TATOGENE ccccccsccces 
MEE LIOCEN ET .scccccsscss 
— 
| Stringocephalus, Megalodon, Orthonota, Pterinea. 
ae Discites, Goniatites, Porcellia. 
VA aticopsis, Platyschisma, Metoptoma, Productus. 
Aviculo-pecten, Anthracosia, Conocardium, Sedgwickia 
ene Aulosteges, Strophalosia. 
Myalina, Bakewellia, Axinus, Edrnondia. 
Ceratites, Naticella, Platystoma, Koninckia, Cyrtia, 
Monotis, Myophoria, Pleurophorus, Opis. 
‘Belemnites, Beloteuthis, Geoteuthis, Ammonites. 
Alaria, Trochotoma, Rimula, Pileolus, Cylindrites, 
Waldheimia, Thecidium, Spiviferina, Ceromya. 
Gryphea, Hippopodium, Cardinia, Myoconcha. 
Coccoteuthis, Leptoteuthis, Nautilus. 
Spinigera, Purpurina, Nerinzea, Neritoma. 
Pteroperna, Trichites, Hypotrema, Diceras. 
Trigonia, Pachyrisma, Sowerbia, Tancredia. 
Crioceras, Toxoceras, Hamulina, Baculina. 
Requienia, Caprinella, Sphera, Thetis. 
Belemnitella, Conoteuthis, Turrilites, Ptychoceras. 
Hamites, Scaphites, Pterodonta, Cinulia, Tylostoma. 
Acteonella, Globiconcha, Trigonosemus, Magas, Lyra. 
Neithea, Inoceramus, Hippurites, Caprina, Caprotina. 
Beloptera, Lychnus, Megaspira, Glandina, Typhis. 
Volutilithes, Clavella, Pseudoliva, Seraphs, Kimella. 
Conorbis, Strepsidura, Globulus, Phorus, Velates. 
Chilostoma, Volvaria, Lithocardium, Teredina. 
Spirulirostra, Aturia, Vaginella, Ferussina. 
Halia, Proto, Deshayesia, iso, Cassidaria, Carolia. 
Grateloupia, Artemis, Tapes, Jouannetia. 
Argonauta, Strombus, Purpura, Trophon. 
Yoldia, Tridacna, Circe, Verticordia. 
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