CONTENTS 



Page 



Introduction I 



Acknowledgments 2 



Rhynchonelloid morphology 3 



Beak characters 3 



Interior characters of the pedicle valve 4 



Interior characters of the brachial valve 5 



Cardinal process 5 



Hinge plates 6 



Crura 6 



Median ridges, median septa, and camerae 9 



Exterior characters 10 



Ornamentation 10 



Folding 11 



Rhynchonelloid classification 12 



Family and generic arrangement and characters 14 



Family Cryptoporidae 17 



Cryptopora 17 



Mannia 2.2 



Family Basiliolidae 25 



Subfamily Basiliolinae 25 



Basiliola 25 



Eohemithyris 30 



Ncohemithyris 34 



N eorhynchia 34 



Rhytirhynchia 35 



Probolarina 37 



Streptaria 38 



Subfamily Aphelesiinae 41 



Aphclesia 41 



Subfamily Aetheiinae 42 



Aetheia 42 



Patagorhynchia 44 



Family Hemithyridae 45 



Hemithyris 45 



Notosaria 48 



Tegulorhynchia 50 



Plicirhynchia 52 



Family Frieleiidae 53 



Fricleia 53 



Compsothyris 56 



Grammetaria 58 



Family Hispanirhynchiidae 59 



Hispanirhynchia 59 



Sphenarina 62 



Family Erymnariidae 64 



Erymnaria 64 



Unplaced species 66 



References 67 



Explanation of plates 73 



iii 



