26 Rev. T. Salwey^s List of Lichens in Wales. 



Pertusaria crassa. Upon an old tree at Ty Gwyn ; on an old ivy-tree 

 in Cheriton churchyard, Pembrokeshire. 



Thelotrema lepadinum. In great perfection upon old trees at Cors-y- 

 gedol. It grows also upon rocks at Llyn Bodlyn, the only instance 

 I know of its growing upon stone. 



melaleucum. Upon trees at Holyland near Pembroke. 



Lepraria lolithus'^. Very finely upon stones about Cors-y-gedol. 



Variolaria lactea. In great perfection about Barmouth. 



• terricola. Cwm Bychan, Pont Fadog, &c. 



Urceolaria Acharii. This usually grows upon stones occasionally sub- 

 merged, as in rivulets and at the ^di^Q of lakes ; but I once found 

 a very beautiful specimen upon a wall in a very high and dry 

 situation, so finely developed in all its parts, that I could for some 

 time scarcely persuade myself it was not a new lichen, 



Lecidea atrata. Craig Drwg : very scarce. 



atro-alha. Rocks at Llyn Bodlyn. 



fusco-atra. Rocks about Barmouth. 



cechumena, /3 athrocarpa. Rocks behind the Union-house at 



Corwen. 



petr^a. 1 Common. 



— — — — confluens, J 



lapicida. Rocks above Gwastad-annos and Llyn Bodlyn. 



prominula. Rocks about Barmouth. 



parasema (not elmochroma, with which it has been con- 



founded). Upon beech- trees near the House at Crafnant, Cors-y- 

 gedol, &c. 



sanguinaria. Upon rocks and old gate-posts : not uncommon. 



viridi-atra. Walls and rocks : an obscure and puzzling 



lichen. 



geographica 



silacea. 



rc^i ' ^Common. 



(Eden. 



• flavo-virescens._ 



I once found (Ederi in a remarkably high state of development upon 

 a mass of stone, which, upon breaking it, was found to be principally 

 copper ore, to which circumstance undoubtedly the alteration of the 

 plant was owing. 

 scabrosa. Not uncommon, but seldom found in a good state : 



Aberhamfrac, &c. 

 uliginosa. On the road- mud thrown on the top of the wall 



* I have inserted a species of the genus Lepraria because British authors 

 have hitherto, as far as 1 am aware, agreed in retaining this genus. I should 

 be glad however to see not only this genus, but also Variolaria, which is 

 ahuost equally unsatisfactory, rejected altogether from an Enunieratio Li- 

 chenum. Whethnr Fries is right in considering them as the decaying re- 

 mains of more perfect Lichens, or other authors as the commencen)ent of 

 Lichens which require only more favourable circumstances to become more 

 fully developed, I will not venture to decide, though my own opinion leans 

 to the latter view of the question. The genus Isidium is perhaps equally 

 unsatisfactory and ought also to be rejected. 



