6 CONTENTS. 



Chapter I\'. Morphology of the brachia, by Charles E. Beecher— Continued. 



Classification of brachial structures — Continued. Page. 



Ptycholophu.s sta^e 109 



Zug(>l()i)bii8 and plectolopbus stages 109 



Spiroloi)lui8 stage HO 



References H-^ 



Chapter V. Classification of the lirachiopoda 113 



Historical 113 



Principles of classification 1 15 



Classification and synonymy 118 



Atreuiata 119 



Telotremata 121 



Neotremata 129 



Protremata 131 



Diagram illustrating geologic distribution of families 131 



Synopsis of the divisions of Brachiopoda higher than genera 136 



Chapter VI. Index and bibliography of American fossil Brachiopoda 138 



