

46 THE BRITISH FERNS. 
These primary and secondary groups, consisting of orders and tribes, 
will be more readily comparable in the following summary :一 
Spore-cases ringless— 
Fructifications marginal on rachiform fronds 
Fructifications dorsal on flat leafy fronds 
Sori oblong, distinct, longitudinally biserial . 
Sori circular, distinct; spore-cases annularly con- 
crete in a single series . 
D e . ee 
Sori connate throughout the under surface of fertile 
fronds 
Spore-cases having a jointed ring 
Spore-cases not valvate— 
Ring vertical, nearly complete; spore-cases usually 
stalked, gibbous ; bursting transversely ; (recep- 
tacles superficial or immersed) . 
Ring obliquely vertical, nearly complete, narrow ; 
spore-cases crowded, sessile or subsessile, oblique- 
laterally-compressed, bursting transversely ; (re- 
ceptacles elevated) 
Ring sub-oblique, nearly complete, broad; spore- 
cases few, sessile, gibbous, bursting transversely ; 
(sori oligocarpous) 
Ring horizontally or obliquely transverse, com- 
plete; spore-cases sessile or subsessile, bursting 
vertically— 
Ring zonal; spore-cases vertically compressed— 
Sori dorsal ; (fronds rigid) . 
Sori extrorse-marginal ; (fronds pellucid). 
Ring apical; spore-cases oval, crowned by the 
convergent strie of the ring, č. e., radiate- 
striate at the apex, sometimes resupinate . 
Ring rudimentary or more or less incomplete, very 
broad, flat, obliquely-vertical; spore-cases sessile, 
globose . 
Spore-cases two-valved ; (ring rudimentary transverse) . 
OPHIOGLOSSACEE. 
MARATTIACEE. 
MARATTINER. 
KAULFUSSINES. 
DANZINER. 
POLYPODIACEZ. 
POLYPODINEZ. 
CYATHEINER. 
MATONINER. 
GLEICHENINER. 
TRICHOMANINEA. 
SCHIZAINEZ. 
CERATOPTERIDINER. 
OSMUNDINER, 
Of the British Ferns three species only belong to Ophioglossacce, 
and all the rest to the Polypodiacew, those belonging to the latter 

