358 Dr James Stirtx)n on LicJuns. 



Cladonia subsylvatica, Strn. 



Cladonia lacunosa, Del. 



Oadoaia bellidiflora, Sdvoer. 



Stereocaulon tomentosum, Fr. 



Stereocaulon Depreaultii, Dd. 



Roccelia Grayi, sp. nov. 



Thallus albidus vel pallido-albidus, opaeus, vel nonniliil pulver- 

 ulentus, frutieosus, erectus Tel interdum decumbens (alt. specimmis 

 circ. 1 poll), compfessus aut bine inde teretiusculus, versus basin, 

 divaricato-ramosos, sursam fasciculato-ramnlosus, et apicibus fere 

 fascicnlato-fibrillosus Tel pectinatus et interdnm fasciculato-setosus. 

 Tbailus extus, K flavens C intense erytbrinosns, et C seorsum ery- 

 thrinosus ; medolla I sordids caerulescens. Apotbecia ignota. 



The external layer of the stem is densely corneous, and 

 thick with a slender irregular medullary centre composed 

 of loose fibres, external to which, and even intermingling 

 with them, are seen greenish gonidia. 



This lichen offers certain analogies to the genus Siphula, 

 but as the reactions are those of Bocdla as well as the 

 dense corneous external layer, I have no alternative but to 

 rank it under the latter genus. 



Usnea longissima, Ach. 

 Alectoria jubata var. chalybeiformis, Ach. 

 Alectoria cincinnata, Fr. 

 Alectoria subsannentosa, 



Similis AL sarmerdosm, Ach., sed medulla K — C — et I pallide 

 caerulescens ; ThaUus K — C flavens. 



The main stems are flattened at the axills as in several 

 species of Chlorea. as constituted by Nylander, but their 

 structure is entirely that of AUctoria. The specimens in 

 hand are well developed, nearly a foot in length and 

 densely matted, especially at the attenuated almost capil- 

 lary apices. The reactions of the other species, viz.. AL 

 cincinnata are well developed and unfailing — medulla K — 

 C pallide erythrinosa. 



Cetraria aculeata, Fr. 

 Platysma lacunosum, Ach. 

 Xephroma arcticum, Fr. 



Peltigera apbtbosa, Hffm. 

 Peltigera spuria, Ach. 



