262 Rev. T. Salwey^s List of Lichens gathered in Wales. 



observe that Dillenius mentions two varieties of the /3 papyracea, 

 both of them having the margins of the lobes of the thallus cris})ed 

 and mealy, and one of them, in addition to this, having the thallus 

 itself sprinkled with mealy warts. Now my own observation coincides 

 entirely with this, except that the variety without the mealy warts is 

 a great deal thinner in the substance of the thallus than the other ; 

 often indeed so much so, that it is impossible to detach it from the 

 inequalities of the surface of the stone which it follows, without tear- 

 ing it. J7iis is the var. which I have hitherto regarded as the ft pa- 

 py7-acea of Ach., and the name is very applicable. The substance of 

 the thallus in the other variety, the one sprinkled with mealy warts, 

 is thinner than in the resupinata, but thicker than in the last-de- 

 scribed variety ; and it is this with the mealy warts which I have re- 

 garded hitherto as the parilis of ' Eng. Bot.' and still believe it to be 

 so, but whether the parilis of Sweden I cannot say, having no sj)e- 

 cimen to refer to. Acharius describes this latter as " granulis nigris 

 obsessus," which looks like our parilis, for I have a specimen covered 

 with dark mealy warts, and which on both sides is almost black : 

 usually the colour of this var. beneath is of a dark olive-brown in- 

 clining to black, smooth, but wrinkled, and only sparingly beset with 

 the black fibrous roots which attach it to the stones or mosses on 

 which it grows. Wahlenberg does not appear to have met with our 

 variety with mealy warts, for he says of his ft papyracea, " omnino 

 Isevis est, et L. herbaceum apprime refert," which corresponds well 

 enough with the variety without warts, but not with that variety 

 which has been figured in ' Eng. Bot.' as parilis : I have a single spe- 

 cimen of the plant without warts in fruit. Dillenius speaks of it as 

 barren, " absque peltis." Upon the whole, I am inclined to think it 

 still doubtful whether our var. with powdery warts, the parilis of 

 ' Eng. Bot.,' may not also be the parilis of Acharius, as he consi- 

 dered it when he published his ' Lich. Univ.' ; but in the absence of 

 authentic specimens it is perhaps safer for the present to refer both 

 our varieties to Neph. resupinata, ft papyracea. 



Since the above was put in type I have received the following ad- 

 ditional habitats of Welsh Lichens from my friend Mr. Ralfs. 

 Verrucariaviridula. Common upon the walls on the road-sides about 



Dolgelley. 

 Endocarpon Hedwigii, y. Cader Idris, as you ascend to Gen Graig ; 

 and by a small stream as you ascend from Llanberis by the side of 

 Glyder towards TwU-du. 

 Lecidea cornea. Dolgelley and Bangor. 



aurantiaca. Bangor. Not uncommon. — T. S. 



Lecanora sophodes. Bangor. 



squamulosa. Abundant in several places about Dolgelley. 



Parmelia isidio'ides. Not uncommon on the trees by the waterfall at 



Dol-me-lyn-llyn, but in fruit only upon one tree. 

 Placodium microphyllum. In fruit near the stations of the Farm, isi- 

 dio'ides. 



