xii CONTENTS 



Part V. The genera of the suborder Pentameroidea — Cont. 



Superfamily Pentameracea — Cont. Page 



Generic and evolutionary trends 165 



Loss of interareas and development of a planarea 165 



Rostration 165 



Reversion of normal convexity 165 



Trilobation 165 



Ornamentation 165 



Loss of the ventral septum 166 



Development of a cruralium 166 



Parallel trends 166 



Summary 166 



Family Camerellidx 166 



Camerella 167 



Branconia 168 



Parastrofhtnella 169 



Anastrofhia 169 



Metacamerella 170 



Family Pentameridas 170 



Subfamily Gypidulinse 171 



Clorinda 171 



Barrandella 173 



Gyfidula 173 



S'teberella : 175 



Pentamerella 176 



Zdimir 177 



Subfamily Pentamerinae 177 



Lasves 177 



Pentamerus 177 



Pentameroides 179 



Lissocoelina 179 



C afelliniella 179 



Holorhynchus 180 



HarpidiuTn 180 



Costatffi 180 



Rhifidium 180 



Conchidium 181 



Brooksina 183 



Cymbidium 183 



Platymerella 184 



V'trgiana 185 



Family Stricklandidas 186 



Stricklandta 187 



Appendix 189 



? Superfamily Rhynchonellacea 189 



Rhynchocamara 189 



Liocoelia 189 



Index 257 



