LIMBORIEiE. 69 



7. P. SULPHUREA, nov. sp. Sporidia not contained in 

 asci, free, innumerable, minute, linear-oblong, rounded 

 at each extremity, yellow. Plate XXIX. fig. 5. 



On sandstone rocks. Niton, Isle of Wight ! Mr. Borrer, 



Thallus crustaceous, pale-olive, minutely verrucoso- 

 rugose, cracked, becoming denuded of the cortical layer, 

 and then covered with a pale sulphur-coloured powdery ef- 

 florescence, just as if flour of brimstone had been scattered 

 over the rock. Apothecia numerous, rather large, scattered, 

 immersed in the thallus^ the black apex only visible. Pe- 

 rithecium dimidiate, straight at the base : nucleus, pale. 

 Can this be a state of P. litJdnay {Ferr. lithina, TayL 

 Fl. Hib.) ? 



Cliostomum corrugatum, Fries. (L. Ref. 455, 1831,) 

 is, undoubtedly, a fungus parasitic on the crust of Lecidea 

 Ehrhartiana, Ach. (Liclieii BhrUartianus, E. Bot. 1136). 

 Observation proves that the sporidia of Cliostomicm corru- 

 gatum are not contained in asci, but are free, innumerable, 

 very minute, linear-oblong, pale-yellow (see Plate XXX. 

 fig. 1.) whilst those of Lecidea Ehrhartiana (see Plate 

 XXX. fig. 2.) are very minute, broadly linear, rounded 

 at each extremity, uniseptate, pale-yellow, 8 in each ascus ; 

 consequently the plants have nothing in common. Fries 

 considers Lecidea Ehrhartiana as the apothecia of Far- 

 melia varia, {Lichen varius, E. Bot. 1GG6,) parasitic on 

 the crust of Cliostomum corrugatwn, and makes it in con- 

 sequence his var. 2 parasitica of Parmelia varia, (L, Bef. 

 159), but this is disproved by the sporidia of Parmelia 

 varia being of a regular elliptical form, margined, and 

 filled with round granules. (See Plate XXX. fig. 3.) 



The specimens examined wxre from Livermere, Suffolk ! 

 and near Cotteshall ! Mr. Borrer remarks, in lit, 1850, 



