12 
FERNS AND FERNERIES . 
Fern (’Polystichum aculeatum ); the Mountain Lastrea 
(Lastrea montana) ; the Rigid Buckler Fern ( Lastrea 
Fig. 6. 
rigida) ; the Crested Buckler Fern (. Lastrea cristata , 
var. Spinulosa ); the Broad Buckler Fern ( Lastrea 
dilatatd) ; the Brittle Bladder Fern ( Cystopteris fragilis )j 
