350 STRATIGRAPHICAL GEOLOGY 



phalus, with the Neozoic types of Trochus, Turritella, Scalaria, 

 Ccelostylina, Ceriihium, and Pseudomelania, as well as peculiar forms 

 which have been named Naticella, Chilocyclus, and Ptychostoma. 



Of Lamellibranchs Posidonomya, Megalodon, and Myophoria 

 (which is probably inseparable from Schizodus) connect the fauna 

 with Palaeozoic life, while certain genera are especially Triassic, 

 such as Halobia ( = Daonella\ Monotis, Cassianella, Trigonodus, and 

 Anoplophora. There are many representatives of Pteria, Gervillia 

 (Hcernesia), Pecten, and Lima ; and the following genera make their 

 first appearance, Velopecten, Plicatula, Mytilus, Lucina, Sfihceriola, 

 Cardita, Palceocardita, Unicardium, Protocardium, and Homomya. 



The Brachiopoda include the last survivors of the ancient genus 

 Spiriferina, with some specially Triassic forms, such as Koninckina, 

 Thecospira, and the Athyroids which Bittner has separated under 

 the names of Tetractinella and Pentactinella. Besides these, species 

 of Terebratula and Bhynchonella are abundant. 



Among Echinoderms Cidaris, Hemicidaris, Mesodiadema, and 

 Tiarechinus make their appearance, and the last is restricted to the 

 Trias. Of Crinoids Dadocrinus, Isocrinus, and Encrinus are found. 



Corals (Anthozoa) also occur, especially in the limestones of the 

 Upper Trias, and belong chiefly to Cladophyllia, Calamophyllia, 

 Thecosmilia, Isastrea, and Thamnastrea. 



Calcareous algae, however, are the chief limestone builders, and 

 have been described under the names of Diplopora and Gyroporella. 



2. Lacustrine and Terrestrial Fauna 



This is found in the Bunter and Keuper Series of England, 

 Germany, and France, the animals being those which lived in or 

 near the large inland salt lakes and lagoons, the plants those which 

 grew on their borders and by the rivers which ran into them. 



Plantse. The ferns are represented by the following genera : 

 Anomopteris, Chelipteris, Ohladophlebis, Lacopteris, Coniopteris, 

 Neuropteridium, and Tceniopteris. The Cycads Zamites, Otozamites, 

 and Pterophyllum are common plants. Conifers are represented by 

 Voltzia, Albertia, Baiera, and Schizolepis. The horse-tail Equisetites 

 also makes its appearance, as well as a new genus Schizoneura. 



Mollusca. Shells of this class are very rare, but a few resem- 

 bling Unio and Anodon have been found, and others in the English 

 Keuper which resemble Thracia, Goniomya, and Pholadomya. 



Crustacea. This class is represented only by the Phyllopod 

 Estheria, which is abundant in the Keuper. 



Pieces. Eemains of many kinds of fish occur, especially in 

 the Keuper Beds, the more important genera .being Acrodus, 



