530 DR LAUDER LINDSAY ON NEW LICHENICOLOUS MICRO-FUNGI. 



brownish, or yellowish ; but there is no such reaction in the Microthelice, which 

 Mr Berkeley refers to Celidium. Nor can I conceive any proper ground for 

 assigning the parasite of Lecanora polytropa v. intricata to Abrothallus, which is 

 itself a provisional and pseudo-genus. 



Indeed, I am utterly at a loss to comprehend the principles of Mr Berkeley's 

 classification in the parasites above referred to ; and I am led to regard his opinion 

 as another of the many illustrations that may be cited of the diversity between 

 lichenologists and fungologists regarding the nature and affinities of a large and 

 important group of parasites, which have been fully studied by neither class of 

 observers, and are yet, therefore, most imperfectly known. And further, his 

 (quite recent) opinion I accept, as strongly confirmatory of the propriety of estab- 

 lishing a provisional group of Fung o -lichens, and of resting contented with placing 

 therein such doubtful organisms as the Microthelice, which I have hereinafter 

 and elsewhere described,* instead of engaging in fruitless and interminable dis- 

 cussion as to whether they axe fungi or lichens. 



When they become more generally studied and more thoroughly known, it 

 may prove that some of the Microthelice in question are not parasitic or athalline, 

 really possessing a proper thallus ; or they may occur — as not a few true lichens 

 do — both in the thalline and athalline state. 



Only in certain cases, in describing the parasites, which form the subject of 

 the present communication, have I ventured to assign names, viz., in the cases of 

 those which may be considered typical or representative. In other cases— by 

 reason of their resemblances to certain types or to each other, of the imperfec- 

 tions of their structure, or for other causes — I have deemed it preferable for the 

 present not to assign names, either generic or specific, though all these doubtful 

 parasites are grouped provisionally, for convenience in future study and reference, 

 under the pseudo-genus Microthelia. I have little doubt that when the parasites 

 in question, as well as the parasitic Micro-lichens and Micro-fungi that have been 

 described by other authors, are more thoroughly studied and known, the same 

 type or species will be held to include several of those which at present appear 

 distinct. There will be not only a certain reduction, but abolition, of genera 

 and species, of which there is at present a most confusing redundancy.! 



Description of Illustrative Specimens. 

 I. Torula lichenicola. 



A. Parasitic on thallus or apothecia (or both) of Lecanora suhfusca, Ach. 

 1. Scotch forms. 



(«) Corticolous : Craig Choinich, Braemar, Aug. 1856, W. L. L. — Parasitic both on 

 thallus and apothecia in one specimen of ordinary form of the Lecanora. The 



* " Otago Lich. and Fungi," pp. 436-442. 



-f- An excellent illustration is to be found in the group of " Parasitic Micro-lichens" (antea citat.) 



