280 DK, LAUDER LINDSAY OS AKTHOXIA MELASPEKMELLA. 



be said to exist, and gonidia are absent ; but the hymenial gela- 

 tine gives a wine-red with iodine. 



Ahrothalhis SmWiii, TuL, described by the fangologist Tulasne 

 as a Lichen *, is regarded by the lichenologist ^N'ylander as a 

 Fungus f • I have elsewhere J shown that this species differs 

 from another, which very generally accompanies it as a parasite on 

 Parmelia saxatiUs, Ach. {A. oxijsporits^ TuL), in the absence of a 

 blue reaction with iodine ; the absence of spermogones and the 

 presence of pycnides ; and the possession of brown, 1-septate 

 spores, resembling (save as to size) t\io^e oi Artlionia melasper- 

 mella. But, notwithstanding these marked differences, which, 

 after all, are not greater than those characterizing certain 

 species of such genera as ArtJionia and Lecidea^ it seems unna- 

 tural to separate into two different orders of Cryptogams plants 

 otherwise possessed of similar characters, and which affect the 

 same lichen as parasites, producing or occupying the same anamor- 

 phoses, or deformities, of its thallus. I have been strengthened in 

 this conviction by the circumstance that in New Zealand I found 

 an intermediate form or species of AbrothaUus, to which I have 



given the name AhrotTiallus Curreyi^ which resembles A. SmitMt^ 

 quoad its apothecia, and A. oxysjporus, quoad its reaction with 

 iodine, and its spores (the spores sometimes, however, in A. Cur- 

 reyi showing a tendency to division into two). In the latter 

 species I have not succeeded in detecting either spermogones 

 or pycnides ; but my specimen is unique, and either or both may 

 confidently be looked for in any suite of specimens. On a sterile 

 specimen of Parinelia Iwvigata, Ach., var. sinuosa, Lin., in the | 



Hookerian Herbarium [from Wollanaboon, Sikkim, Himalayas, 

 reg. temp. 10,000 ft., Dr. Hooker], I found a form of J. Oiirreyi 

 affecting buUosities of its thallus, similar to those produced by 

 A. sysportcs in Platysma glaucum^ a form characterized by cres- 

 cent-shaped, colourless, bilocular [sometimes polari-bilocular or 

 physcoid] spores. 



Some of the plants described by the older lichenologists as 

 Lecidea dryina appear to be Fungi, According to Nylander, X- 

 dryina^'Flk., is one (Schizoxylon dryinum, Flk. §). Here the hyme- 



* M^m. Lich. p. 113. 



asiticus 



including A, Welwitschii^ Tul., and A. microspermus^ Tvl 

 "Monograph of the genus Ahrothallui 



" Quart. Joum 



Science 



Scand 



