226 G. i?. Wieland — American Fossil Cycads. 



18. The Development of the Antherozoids of Zamia. 



Bot. Gaz., pp. 16-22, figures 1-5, July, 189 7. 



19. Notes on the Fecundation of Zamia and the Pollen 



Tube Apparatus of Gingko. Bot. Gaz., pp. 225-235, plate x, 

 October, 1897. 



20. Scott, D. H. — The Anatomical Characters presented by the 

 Peduncle of Cycadacese. Annals of Botany, vol. x, pp. 399-419, 

 plates xx and xxi, London, August, 1897. 



21. Lang, William H. — Studies on the Development and Mor- 

 phology of Cycadean Sporangia. Ann. Bot., vol. xi, pp. 421-438, 

 plate xxii, London, September, 1897. 



22. Worsd'ell, W. C. — The Vascular Structure of the Sporo- 

 phylls of Cycadacese. Ann. Bot., vol. xii, pp. 203-241, plates 

 xvii and xvii, London, June, 1898. 



23. Ikeno, S. — Untersuchungen tiber die Entwickelung der 

 Geschlechtsorgane und den Vorgang der Befruchtung bei Oycas 

 revoluta. Mit Tafeln viii-xund zwei Autotypien. Jahrbucher fur 

 wissenschaftliche Botanik, Band xxxii, Heft 4, pp. 557-600, 

 Leipzig, 1898. 



24. Worsdell, W. C. — The Comparative Anatomy of certain 

 Genera of the Cycadaceas. — Journ. Linn. Soc, London, July 1, 

 1898. 



25. Marsh, O. C. — The Jurassic Formation on the Atlantic 

 Coast. Supplement. American Journal of Science, vol. vi, pp. 

 115-116, August, 1898. 



26. Cycad Horizons in the Rocky Mountain Region. 



Amer. Jour. Sci., vol. vi, p. 197, August, 1898. 



27. Seward, A. C. — Fossil Plants, vol. i, London, 1898. 



28. Ward, Lester F. — Descriptions of the Species of Cycade- 

 oidea, or Fossil Cycadean Trunks, thus far determined from the 

 Lower Cretaceous Rim of the Black Hills. Proceedings of the 

 U. S. National Museum, vol. xxi, pp. 195-229, Washington, 1898. 



EXPLANATION OF PLATES. 

 Plate II. 

 Cycadeoidea ingens, "Ward (type). 



Male plant; showing flower bud at summit. 

 One-sixth natural size. 



Plate III. 



Cycadeoidea ingens ; same specimen. 



Longitudinal section through male flower. 



For details, see diagram in text, p. 221, figure 1. 

 Twice natural size. 



Plate IV. 

 Cycadeoidea ingens ; same specimen. 



Figure 1.— Cross section through middle of male flower; showing sori and 

 bracts. 



Figure 2. — Cross section through base. 



For details, see diagram in text, p. 221, figure 2. 

 Both figures are twice natural size. 





