308 



INDEX OF GENERA. 



Surirella 7, 15 



Sycotopus 73 



Synedra 7, 15 



Syntrilasma 277 



Syringothyris 275 



Tabellaria 16 



Tachyphonus 106, 171 



Tanagra , 171 



Tantilla 197 



Tapirus 183 



Taxocrinus 133 



Tellimya 58 



Tellina 56 



Tentaculites 254 



Tetracyclic 14 



Tetradecapoda 46 



Thamnophilus 107 



Thamnophis 197 



Theca 227, 235 



Thoropa 194 



Thymallus 80 



Tigoma 70 



Tornatina 58 



Trachycephalus 194 



Trachydermon 60 



Trematocrinus 167 



Trichodesma 227, 230 



Trigonocephalus 198 



Trigonotreta 275 



Triloculina 73 



Trirhabda. 205, 219 



Trisotropts 104 



Trochoceras 263 



Trochocopus 77 



Tropidoclonium 190, 197 



Tropidodipsas.. 198 



Trutta 80, 85 



Trypopitys 227, 234 



Unio , 75, 88 



Uraaidea 82 



Venericardia 71, 73, 184 



Venus 57 



Vivipara 71 



Volutilithes 71, 73, 184 



Xestobium 224, 227 



Xyletinus 237 



Xypbosura 43 



Yoldia 73 



Zaphrentis Ill 



