540 DIl LAUDER LINDSAY ON NEW LICHEN ICOLOUS MICRO-FUNGI. 



immersed in the thallus of the host, only the black apex being visible on the 

 surface. The whole length of some latinise is dotted over with the parasite, while 

 others are unaffected. My notes, made in 1857, do not record, unfortunately, 

 the colour, size, or form of the sporidia. 



5. M. rugidosaria. Parasitic on apothecia of Placodium rugulosum, Nyl. 

 (" Chil." p, 193 ;) Tasmania, Stuart, in Herb. Kew ; saxicolous. 



The apothecia, which are of a deep orange-red, are abundantly studded over 

 with the very minute, black, punctiform, or papillseform conceptacles of the 

 parasite. The latter are prominent under the lens, especially when the apothecia 

 are moistened, from the striking contrast of colour. They are semi-immersed in 

 the epithecium of the Placodium. Parapl^ses very delicate and filiform. 

 Asci as long as the paraphyses ; -0016" long, -0005" broad ; 8-spored. Sporidia 

 0004" long, '00016'' broad; 1-septate ; soleaform ;* brown. Both asci and sporidia 

 resemble those of the microspermous and microsporous forms of Abrothallus 

 Smithii. 



(a) Having similar sporidia — brown, soleaform, 0005'' long, -00016'' broad— is 

 a similar parasite (which may prove referable to M. rugulosaria, or to the same 

 type to which it may hereafter itself be referred) that affects the thallus of 

 Thelotrema lepadinum, Ach. ; on Holly, Ireland, Carroll. Its perithecia are 

 black and sub-verrucarioid, resembling those of Verrucaria fusiformis or epider- 

 midis. These sporidiiferous perithecia are accompanied by others containing 

 stylospores, like some of those of Lecidea abietina ; narrowly ellipsoid ; -00033" 

 long, -000111" broad ; pale yellow. Both forms of perithecia are probably refer- 

 able to the same parasite. 



The thallus of T. lepadinum is also affected by Nesolechia Nitschkii, Korb. (Par. 

 p. 462), which has minute, oblong-sub-bacillar, simple, hyaline sporidia; and 

 by Stenocbye eusporum, Nyl. 



(b) Another Irish specimen, sent me as a Sphceria, by Carroll, in August 

 1856, from Mangerton, County Kerry, on a tartareous, white, much areolate, 

 sterile thallus (which cannot be referred to its proper species), has figure-8- 

 shaped, 1-septate, deep brown or olive sporidia or spores ; 00033" long, and 



00025" broad. The perithecia are largish and verrucarioid ; very black; vary- 

 ing greatly in size and form ; in the young state papilkeform, in age flattened 

 and lecidioid ; they are scattered on the thalline areola?, and are very conspicuous 

 on the whitish or cream-coloured thallus. 



The plant has externally the facies of Coniothecium lichenicolum , to which it 

 may really belong.f Mr Cooke, who examined it, describes the contained repro- 

 ductive corpuscles, which may be either sporidia or spores, as " Toruloid spores." 



* Frequently erroneously written solce/orm. Soleaform sporidia are necessarily 1-septate. Vide 

 definition of the terra in " Otago Lich. and Fungi," foot note, p. 447. 

 t Fide p. 519. 



