TABLE OF CONTENTS. 



PREFACE xiii-xv 



GASTEROPODA, of the Upper Helderberg, Hamilton, Portage and Chemung groups 1-138 



Platyceras : Descriptions of species 1-21 



Platyostoma : Descriptions of species 21-30 



Strophostylus : Descriptions of species 30-32 



Macrocheilds : Descriptions of species 32-34 



Cyolonema : Descriptions of species 34-39 



Loxonema : Descriptions of species 39-49 



Callonema: Descriptions of species 50-54 



Kiomphalus: Descriptions of species -54-63 



Pleurotomaria : Descriptions of species 64-88 



Murchisonia : Descriptions of species 89-93 



Bellerophon, of the Upper Helderberg — Chemung groups .... 94-1^53 



Species of the Upper Helderberg group - 94-99 



■<ies of the Hamilton group 100-117 



Species of the Chemung group 117-121 



Distribution of species 121, 122 



Cyrtolites, subgenus Cyrtonella: Descriptions of species. . . . 123-126 



Porcellia: Description of species 126-128 



Addenda to the GASTEROPODA : Loxonema, PAi^OTROCHUs^and Turbo . 129-137 



Note on Euomphalus Decewi : Pleuronotus 137,138 



The Louisville limestones: Note on the Hydraulic beds and associated lime- 

 stones at the Falls of the Ohio 139-147 



Note on the Black Slate succeeding the Hamilton limestones at the Falls 

 of the Ohio 148-154 



PTEROPODA, of the Palaeozoic formations 155-216 



Tuntaculites : Historical sketch ... 154-158 



Distribution of species . . 160-162 



Generic features and relations ... 163-166 



Descriptions of species 166-175 



Styliola : History, generic features and relations, and distribution . . 175-178 



Description of species 178-182 



Coleoprion : Historical sketch and description of species .... 183, 184 

 Coleolub : Generic features and descriptions of species 184-190 



