ioo The Scottish Naturalist. 



Ch. Soleirolii, but their rugose thalli form a barrier to such a 

 classification. No mention, besides, is made of the condition of 

 the axes in the description of these two species, which cer- 

 tainly differ considerably from the others included under CJdorea. 

 But even if an analysis of the stems of these two should prove 

 that they are associable with those of the series in question, I 

 hold there are sufficient grounds for the separation of the two 

 groups into a distinct genus. In this belief, I have thought it 

 right to give expression to this view by constituting a new genus, 

 under the name Eumitria. 



I may mention that in all the seven specimens the thin rufes- 

 cent layer mentioned above is tinged a somewhat deeper red by 

 K ; also in the specimens from Madeira the thallus externally is 

 slowly tinged a purplish red by K, a colour produced, in all 

 likelihood, by the same rufescent layer. Lastly, apothecia and 

 spores are exactly as in Usnca. 



(i.) Eumitria Bailey i sp. nov. — Thallus pallide glaucescens vel 

 pallide cinerascens, laevis, rigescens, erectus vel prostratus 

 (crassit. basi saepe 2 mm., longit. (4-7) - pollicaris), ramosus, 

 ramis attenuatis et saepe incurvis vel contortis, longe et 

 crebre fibrilloso-ramulosis ; apothecia (in uno specimine) 

 pallide carnea, mediocria, fibrilloso-ciliata, subtus laevia ; 

 fibrillar medullares K flaventes. 



Brisbane (F. M. Bailey), Fernando Po (G. Thomson). 



Eumitria implicita sp. nov. — Similis praecedenti sed humilior 

 vel similis Usnca floridcc. Thallus pallidus vel pallide 

 lutescens. Fibrillse medullares (K — ) et thallus extus K 

 sordide rubens (reaction e tarde patefacta). 



Eumitria firmula sp. nov. — Similis Usnece. ccratince. robustae. 

 Thallus erectus et rigidus, fibrilloso-ramulosus, papilloso- 

 asper aeque ac receptacula apotheciorum ; fibrillar medul- 

 lares K flaventes. 



Fernando Po (G. Thomson). 



There are two forms from Africa, one much more robust and 

 rigid than the other (alt. 3-5 inches), but scarcely separable. 



The genus Usnca, although the most highly organised of all 

 genera of lichens, is perhaps in the most unsatisfactory condition 

 as regards the discrimination of species. The botanical charac- 

 ters derivable from external habit and configuration are very 



