UNITED STATES 



EXPLORING EXPEDITION. 



DURING THP] YEARS 



1838, 1839, 1840, 1841, 1842, 



UNDER THE COMMAND OP 



CHARLES WILKES, U. S. N. 



ATLAS. 



BOTANY. 



CRYPTOGAMIA. 



F I L I C E S, 



INCLUDING LYCOPODIACE.E AND HYDROPTERIDES. 



BY 



WILLIAM D. BRACKEN KIDGE. 



BY AUTHORITY OF CONGRESS. 



PHILADELPHIA: XX &^|JAvgg^ 



C. SHERMAN, PRINTER. 



1 8 5 5. 



