24P C R Y P T O G A M I A; 
C L-A S S XXIV. 
C Pv Y P T O G A M I A. 
clafs comprehends fuch plants, wliofe fni^ification is 
fo finally as not to he examined hy the naked eye^ and is 
of a very peculiar conftruBion, 
The ferns are the frjl divifion in order ^ whereby is meant 
fuch plants as are dorfiferous, or bear the fruit on the 
hack of the leaf of which the following are the charahie-^ 
rifiics. 
The cup is a fquama, growing out of the leaf opening, on 
one of its ftdes\ under which there are pedunculated glo- 
bules^ each of which is girt with an elafiic ring^ which 
breaks elaftically and fheds dufl. ' ''>■ 
E Q^U I S E T U M. Horse-tail. 
T he frudifications are placed in an oval, oblong 
fpike. Each is orbicuiated, open at the bale, 
many valves being connedled in a plain apex. 
Sylvaticum. Wood Hcrfe-tail with a fpiked ftalk, 
opening at the bafe with many valves. In woods and 
moifi; places. Per, May, 
Arvenfe, Corn Horfe-tail with a naked item bearing 
fruit. Per, March, i 
Paluftre, Marfh Horfe-tail with an angulated ftalk, 
and quite fimple branches. In watery places. Per, June. 
' ~ ' Fhiviatile. 
