92 BRITISH FERNS. 
opposite, distant, linear, slightly drooping and pin- 
natifid; the pinnules crowded, adnate, entire and 
rounded at the extremity; the habit is slender, deli- 
eate and very fragile; the texture thin and almost 
membranaceous; the colour pale green. The fertile 
frond differs in being much taller and more robust, 
and in haying the margins of the pinnules convolute, 
and the pinnules themselves are thus rendered nar- 
clusters of seeds become confluent, and are nearly con- 
cealed by the semi-bleached, semi-membranous margin 
of the pinnule. 
_ The Marsh Fern occurs in every country of Europe; 
in Africa; in the Atlantic Islands and in North and 
_ South America. In Great Britain it must be con- 
_ sidered local, but its distribution is very general, It 
urs only on those boggy heaths where the soil is so 
_ Moist and light that its caudex can extend itself with 
-Tapidity and freedom; in such situations it is found in 
undance. It may be observed that, as a rule, 
