382 Class XXIV. Order I. 



of the frond ; indusia squamiform, connate in the form 

 of berries and not expanding. 



450. STRUTHIOPTEKIS. Capsules densely covering 

 the back of the frond ; indusia squamiform, marginal, 

 opening internally. 



451. ASPLENIUM. Sori linear, transversal, scatter- 

 ed ; indusia arising from the lateral veins, and opening 

 towards the rib. 



452. PTERIS. Sori continuous, linear, marginal : 



' O ' ' 



ifidusiuni from the inflected margin of the frond, open- 

 ing inwards. 



453. WOODWARDIA. Sori oblong, distinct, straight, 

 parallel wiih the ribs of the frond on either side; in- 

 dusia superficial, arched, opening inwards. 



454. ADIANTUM. Sori oblong or roundish ; indusia 

 membranaceous, arising from the margin of the frond 

 and opening inwards. 



455. DICKSONIA. Sori punctiform, marginal, round- 

 ish, and distinct ; indusium double, one superficial, 

 opening outwards, the other marginal and opening in- 

 wards. 



CRYPTOGAMIA. 

 FIL1CES. 



441. EQUISETUM. 

 EQUISETUM HYEMALE. L. Rough Horsetail. Scouring Rush. 



Stem naked, very rough, mostly branched at base ; 

 sheaths whitish, black at the base and summit. 



Found in moist woods at Lynn, and elsewhere. Stems erect, 

 without branches, except at base, hollow, naked, furrowed, the 



