﻿Fig. 1 .— Cycadeoidea marylandica. The earliest described American fossil cycad. 



Discovered about I860, by Philip Tyson in the iron ore beds of the Potomac Formation of Mary- 

 land between Baltimore and Washington. From an original daguerreotype first sent to Sir 

 William Dawson and afterwards by him to William Carruthers, but only recently published 

 as Plate LXXXII, U. S. Geological Survey Monograph XLVIII. Reproduced through the 

 courtesy of the officers of the Geological Survey. 



This splendid and historically important specimen formerly belonged to the Maryland Academy of 

 Science, and is now in the collection of Johns Hopkins University. It is shown about one- 

 fourth natural size. At the time of fossilization it was about to enter upon a period of fruit 

 growth. Nearly thirty young fruits are marked in the present view by the groups of bract scars 

 interpolated between the old leaf-bases, and thus obscuring the early spirally symmetric order 

 of these latter organs of the armor. 



