DR LAUDER LINDSAY ON NEW LICHENICOLOUS MICRO-FUNGI. 529 



which affects Lecanora polytropa v. intricata ; to Celidium, M. Stereocaulicola and 

 the parasites on Squamaria crassa and S. saxicola. 



Some of the parasites formerly grouped by me under Microthelia and the 

 fungo-licliens have been transferred to the fungi proper, e.g., Sphceria ventosaria, 

 by Mr Currey. And it is most likely that other members of that provisional 

 genus or group will from time to time be claimed as true fungi. But I find it 

 impossible to perceive the validity of the claim, or the grounds of distinction. To 

 me it appears that Sphceria is quite as nondescript or heterogeneous a genus as 

 Microthelia, and that it passes into Verrucaria by connecting links that defy 

 differential definitions ! In the " Treasury of Botany," Mr Berkeley says that the 

 only distinction between Verrucaria and Sphceria consists in the presence of 

 thalline gonidia ; but, as I have elsewhere * shown, no gonidia can be present 

 in the large group of parasitic rtthalline lichens, in which the apothecia — with or 

 without spermogonia or pycnidia — constitute the plant. In the same work he 

 describes Endothia as distinguished from Verrucaria by its " naked spores." He 

 also apparently regards it as consisting merely of the pycnidia or spermogonia 

 of different lichens (Treasury, p. 1211); but he elsewhere describes " asci" (Brit. 

 Fungology, p. 384) ! I am utterly at a loss to reconcile or understand these 

 diverse and puzzling statements. Moreover, if we may judge from Nylander's 

 description of S. homostegia (Prod. 56), which is flat and maculseform, the 

 Sphcerice are not necessarily papillreform or verrucarioid. Some of them are thus 

 arthonioid ; and there are a few parasitic athalline Arthonice which have quite 

 the fades of Sp>ltceria homostegia, e.g., A. varians, Dav. (Nyl. Scand. 260). 



Mr Berkeley regards M. Umbilicarice and M. Bceomycearia (in my specimens) 

 as having a " distinct crust ;" or, in other words, a proper thallus. This I quite 

 fail to discover, on repeated examination ; the perithecia appearing to me to be 

 indubitably seated directly on an alien (lichen) thallus. No doubt, M. Umbili- 

 carice and M. Bceomycearia may be referred to the Verrucarias ; but only in the 

 same sense in which the whole group of the Microthelice may be so transferred, 

 constituting, with Endococcus or other pseudo-genera, an athalline (parasitic) sec- 

 tion. We have already seen that the botanical " characters" of Verrucaria are 

 in great measure negative; while there can be no doubt, as a genus, it is 

 already much too (confusingly) large and heterogeneous. 



None of my Microthelice have the essential characters of Tulasne's genus Celi- 

 dium (as defined in his Memoire, p. 120, pi. xiv. figs. 9-13, or in my " Otago Lich. 

 and Fungi," p. 448). According to Tulasne, the perithecia are aggregated so as 

 to form maculae, in the centre of which are seated spermogonia, the spermatia 

 being linear and very slender. In the typical species C. Stictarum, Tul.(Mem. 

 p. 122), the iodine-reaction is lichenic ; the hymenium becoming bluish, reddish, 



* Arthonia melaspermetta, p. 282. 

 VOL. XXV, PART II. 6 X 



