S' 



HYMENOPHYIiLUM UNILATEBALE. 305 



Galway. — Dr. Mackay has found it in Cunnemara ; and I have seen 

 specimens from Marm, Eoundstone, and Oughterard. 



WicKLOw. — On many of the rooky hiUs and waterfalls in this county, at 

 GlendaJough, Hermitage Glen, and Powerscourt waterfall, 



Keery. — On rooks and on trees, ascending to their very summits, among 

 the Kerry mountains, and at all the waterfalls about KUlamey ; also in 

 Valentia island. 



CoKK. — Abundant in the glens near Youghal. 



The radicles and rhizomes of H. unilaterale offer no charac- 

 ters by which I can distinguish them from those of H. tun- 

 bridgense : the fronds of both are circinate ; they make their 

 appearance late in the summer months, and usually remain 

 green throughout the winter, turning completely black in the en- 

 suing summer. The frond consists of branched veins, clothed 

 with a membranous wing, the margin of the wings being ser- 

 rated : the wing on the main rachis is less apparent in unila- 

 terale than in tunbridgense ; the pinnae are always convex 

 above, while those of tunbridgense are usually flat : unilaterale 

 has a more erect habit, tunbridgense a more horizontal, and is, 

 indeed, somewhat drooping, so that, on the trunk of a tree, the 

 fronds seem to rest one on another, like the tiles of a bouse. 

 The involucre is very different from that of tunbridgense ; it is 

 elongate, swollen at the base, and its exterior margin perfectly 

 without serratures ; when the capsules are mature, it opens at 

 the top, and, splitting down the middle, remains widely gaping. 



These are very pretty and very easy ferns to cultivate : 

 they may be used as an undergrowth or ground-covering for 

 Trichomanes radieans, but succeed equally well alone. The 

 following plan will be found successful : — First, fill an ordinary 

 flower-pot with wet Sphagnum, and invert it ; then having pre- 

 pared a compost of silver sand, loam, and peat earth, saturated 

 with water, and mixed to a similitude of mortar, and having 



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