CONTENTS xvii 



Page 



5. Development of Bilobites 399 



Developmental Changes in BUobites various .... 402 



Observations 404 



6. Development of Terebratalia obsoleta Dall . . 406 



7. Development of the Brachial Supports in Die- 



lasma and z yqospira 410 



Development of the Loop in Z)te/a.s7na /M?'^«Wm?i . . . 412 

 Development of the Brachial Supports in Zygospira 



recurvirostris 413 



Observations and Correlations 415 



IV. MISCELLANEOUS STUDIES IN DEVELOPMENT 



1. Development of a Paleozoic Poriferous Coral . . 421 



Development of Pleurodictyum lenticulare 422 



General Conclusions 425 



2. Symmetrical Cell Development in the Favositid.e 429 



Summary ... 433 



3. Development of the Shell in the Genus Tor- 



NOCERAS Hyatt 435 



V. PLATES AND EXPLANATIONS 441 



INDEX 597 



