NOTE ON LECANORA RALFSII. 13 



development of the Hymenomycetes is subject to the action of light, 

 it is that those -which have not been exposed to its influence ; those, 

 for example, which have grown in the galleries of mines, in caves, 

 or in hollow trees, take the most curious abnormal forms, their 

 metamorphosis remaining incomplete, or otherwise the whole fungus, 

 preserving its mycelioid nature, its growth is cut short in a mon- 

 strous modification of the mycelium." In admitting this fact 

 generally, it does not, it appears to me, follow the idea which one 

 has of the superior vegetables. I believe that an equal tempera- 

 ture, certain conditions of constant warmth and humidity, ought to 

 have here as much effect as the want of light, and to cause rather a 

 sort of exuberance which is opposed to the formation of the fructify- 

 ing organs, thus a too luxuriant vegetation often puts an obstacle in 

 t lie way of the flowering or fructification of the Phanerogams. 



NOTE ON LECANORA RALFSII (Salwey), Cromb. 

 By the Rev. J. M. Crombie, F.L.S. & G.S. 



In the Rev. Mr. Salwey's" Observations on Penzance Lichens," 

 in the Annals of the Penzance Natural History Society, ii. (1853), 

 p. 144, there occurs the following notice of a supposed new species 

 of Lecidea : — 



No. 34. Lecidea, nova species, gathered with Mr. Ralfs at 

 Lamorna. 



" This is hitherto a unique specimen, though I hope Mr. Ralfs 

 will be able to find more of it. It consists of a thin, closely pressed, 

 crustaceous thallus, of a dusky-green colour, with irregular warty 

 protuberances and flattened scales intermixed. The apothecia, 

 which are extremely minute, have scarcely any border, and are of a 

 dull reddish-brown. Some of them are of a dull fawn-colour ; 

 but this appears to be an older state, in which the disc has been 

 worn away, leaving the pale colour of the apothecium visible." 



Should it prove to be, as I believe it, undescribed, I would venture 

 to call it Lecidea Ealfsii, from its discoverer. 



The plant so named provisionally, does not appear, at least under 

 the proposed name in any subsequent list of British Lichens. Its 

 identification is, therefore, a matter not simply of curiosity, but of 

 importance. Did Salwey rightly conjecture that it was a new 

 6pecies, or is the name proposed merely another synonyme of one 

 previously described ? From authentic information recently ob- 

 tained from Mr. Wm. Curnow, of Penzance, I believe that I am 

 now in a position fully to identify this plant, and, as will be seen 

 from what follows, it has a rather singular and interesting history. 

 Several months ago I received from the above gentleman two 

 specimens of Lecidea Muddii, Salw., to my great delight, as no 

 British Hellenist, save Messrs. Mndd and Salwey, would Beem ever 

 to have seen this lichen, nor does it appear amongst the large col- 

 lection of British lichens from the latter gentleman in the herba- 



