of Burlington, Iowa, and its Vicinity. 



221 



A LIST OF THE GENERA DTSCOVEHED IN THE ROCKS AT liURLlNGTON, SHOWING 

 THE DIFFERENT BEDS IN WHICH THEY HAVE BEEN RECOGNIZED. 



3 



Phillipsia. 



Crustaceans. 



Cephalopoda. 



Gyroceras 



Orthoceras 



I'hragmoceras '? 



Goniatites 



Gasteropoda. 



Porcellia 



Bellerophon 



Euomphalus 



Pleurotomaria 



Murchisonia ? 



Platyceras 



Coniilaria (Pteropod) 



Loxonema? 



Brachiopoda. 



Spirifer 



Athyris 



Nucleospira 



KetziaV 



Productus 



Linc;ula 



Orthis 



Chonetes 



Strophoinena 



MeristaV 



Rhyiichoiiella 



Terebratula 



Discina 



Lamellibranchiata. 



Avicula 



Pecten 



Aviculopecteii 



Cardiomorpha 



Myalina? 



Modiolopsis? 



Edmoiulia V 



Nucula? 



Conocardium 



Echinodermata. 



Actinocrinus 



Agaricocrinus 



Archiocidaris 



Cyatliocrinus 



Codaster 



Dichocriiius 



Forbesiocrinus 



Homocrinus 



Ichthyocrinus 



Megistocriuus 



