CLASSIFICATION. 29 
TRIBE 4. ASPIDIE#. Fructification round, provided 
with a special indusium, rarely naked; stipes not articu- 
lated. 
Percorreris, . . . . . . Plate XXVI. 
een se OS op Plate X XIX: 
eeegrrrnts -. ..  -.. .-. Plate XXXVH. 
STRUTHIOPTERIS. 
BD ail tele en RAR og 1 aa 
eA’. <3 a a). s) Ce Plate XLII. 
TRIBE 5. DAVALLIE#. Fructification at the ends of the 
veins, with an indusium attached at the base and opening 
toward the margin of the segment. 
DEESOMEAM Ys .¢)\-<tocr. 9... Plate XLV: 
The remaining sub-orders are represented in the United 
States by only a few genera, and have no tribal divisions. 
SUB-ORDER HYMENOPHPLLACE#: 
MerenOMANES, © ss. 6 Plate XLVII. 
SUB-ORDER SCHIZHACE#&: 
SCHIZZA. 
Pea NRe > 8 era i ays “Pigte SEL EX, 
SUB-ORDER OSMUNDACE#: 
MMUNAUAS ine), sf degltoaaei,. sete lal 
SUB-ORDER OPHIOGLOSSACEZ: 
BoreveummM 2 oe Piste LY. 
OPHIOGLOSSUM, ........... .. Plate [ABIX: 
For a more detailed account of the classification and 
description of the ferns of North America, I would refer 
the reader to the excellent article, “Filices,’ by Prof. 
Eaton, in the latest edition of Gray’s Manual, and to his 
splendid monograph on the “Ferns of North America,” 
now in course of publication. 
