PLATE XL. 



PAGE 



Figs. 1, 2. Thinnfeldia grantjlata Fontaine 303 



Type specimens from Dutch Gap, Virginia (after Fontaine). 



Fig. 3. Thinnfeldia kotundiloba Fontaine 305 



Specimen from Fredericksburg, Virginia (after Fontaine). 



Figs. 4-7. Thinnfeldia Fontainei Berry 302 



4. Specimen from 72-mile post, Virginia (after Fontaine). 



5. Pinnule of same. X 2 (after Fontaine). 



6. 7. Small distal fragments, White House Bluff, Virginia (after Fon- 



taine) . 



Figs. 8, 9. Thinnfeldia marylandica Fontaine 305 



Type specimens from Arlington, Maryland (after Fontaine). 



539 



