xvi STUDIES IN FOSSIL BOTANY 



CHAPTER IX 



THE FERNS — continued 

 The Botryopterideae — Summary on the Ferns 



PAGE 



I. Botryopterideae 3°5 



A. Zygopteris Group 306 



1. Zygopteris 3°° 



2. Other Genera . . . 3 2 3 



B. Botryopteris Group 325 



3. Botryopteris . . 325 



4. Other Genera . . 333 



5. Stauropteris 336 



6. Affinities of the Family . 340 



II. Summary 346 

 CHAPTER X 



PTERIDOSPERMEAE 



Lyginodendreae 



Introductory Remarks . . . . 355 



I. Lyginodendron 357 



1. The Stem ... 358 



2. The Leaves . 373 



3. The Roots 378 



4. Habit 283 



5. The Seed . 386 



6. The Microsporangia oqg 



II. Heterangium 4 OI 



1. The Stem [H. Grievii) . , Q2 



2. The Leaves . . . . QQ 



3. The Roots . . 4IO 



