THE RIGID BUCKLER FERN. 107 



of Argyle, Berwick, Dumbarton, Forfar, Inverness, 

 Orkney, and Roxburgh ; also in the islands of Arran, 

 Mull, and North Uist. In Ireland, in the counties of 

 Antrim, Clare, Cork, Donegal, Galway, Kerry, London- 

 derry, Mayo, Sligo, Waterford, and Wicklow. In the 

 island of Guernsey. It is found growing from the sea- 

 level to two or three thousand feet above it. 



XXXIIL THE RIGID BUCKLER FERN. 



Lastrea rigida. 

 (Plate VI., Fig. 3, page 59.) 



LENGTH OF FROND. One foot to two feet. 



GENERAL DESCRIPTION. Roots abundant, fibrous. 

 Rootstock, a thick, tufted cormus. Fronds rigid, erect ; 

 stipes about half the length of, or as long as, the leafy- 

 part, scaly, the scales being continued along the rachis ; 

 leafy part triangular, bipinnate, pinnae cone-shaped, in 

 pairs or alternate upon the rachis, and divided into 

 oblong, alternate, indented pinnules, which are arranged 

 in symmetrical order upon the secondary rachides 

 the whole frond having a very elegantly-cut appearance. 

 Fructification consisting of lines of sporangia a line on 

 each side ot the midvein of each pinnule covered by 

 the kidney-shaped indusia characteristic of the genus 

 Lastrea. 



HABITATS. Rocky hollows, in the moist crevices of 

 which the Rigid Buckler Fern often grows abundantly in 

 its own districts. It prefers limestone rocks ; and is, in 

 fact, the only one of the genus Lastrea which prefers 

 rocky habitats. 



WHERE FOUND. In England, only in the counties of 

 Cornwall, Lancaster, Somerset, Westmoreland, and York ; 



i 



