( 53 ) 
The following table shows, placed in juxta-position, 
the especial distinctive features of some species of the 
same genus which are liable to be confused. 
ASPLENIUM ADIANTUM- 
NIGRUM. 
Fronds. Triangular; thelow- 
est pinnaj the 
longest. 
Sori. Near the middle of 
the pinnules. 
CYSTOPTERIS FRAGIL1S. 
Pinn.e. Lanceolate. 
Stipes. Rather long. 
Sori. Confluent when ma¬ 
ture. 
HYMENOPHYLLUM TUN- 
eriegense. 
Fronds. Nearly flat. 
Involucres. Spherical; flat¬ 
tened and spiny on 
the upper edge. 
EASTREA FILIX-MAS. 
I' Ronds. Bi-pinnate. 
PlN N*. Linear. 
Stipes. Short. 
ASPLENIUM LANCEO- 
LATUM. 
Fronds. Lance-shaped; the 
middle pinnas the 
longest. 
Sori. Near the margin of 
the pinnules. 
CYSTOPTERIS REGIA. 
Pinnae. Triangular, ovate. 
Stipes. Short. 
Sori. Distinct when ma¬ 
ture. 
HYMENOPHYLLUM UNI- 
LATERALE. 
Fronds. Convex. 
Involucres. Pitcher-shaped; 
smooth on the 
edge. 
LASTREA CRISTATA. 
Fronds. Pinnate. 
PiNNas. Deltoid. 
Stipes. Long. 
