DR LAUDER LINDSAY ON NEW LICHENICOLOUS MICRO-FUNGI. 537 



Lepraria, Berk, and Broome, of Berkeley's " Brit. Fungology," p. 327; and 2. 

 Spiloma melanopum, Engl. Bot. t. 2358 of 1st edition, which is the Sporidesmium 

 melanopum, Berk, and Broome, of Berkeley's " Brit. Fungol." p. 327. 



III. Sphceria ventosaria, Linds. " Obs. on Otago Lichens and Fungi," p. 439 ;* 

 " Obs. on Greenland Lichens."f 



Parasitic on the thallus of what appears to be Lecidea grossa, Ach., Ingleby, 

 Cleveland, Yorkshire, Mudd ; in my Herbarium. Occurs as minute, black papilla?, 

 intermixed with the apothecia of the Lecidea. Externally the parasite has the 

 character, as it has the position, of certain verrucarioid spermogonia, e.g., in the 

 genus Lecidea; and it has also the facies of Endococcus or Microthelia. No 

 distinct asci are visible ; but the hymenial gelatine showed a beautiful carmine 

 or violet colour with iodine, just as many true lichens do. Sporidia minute, pale 

 brown, oblong, with rounded ends, with or without double contour, according to 

 age ; 1-septate— septum indistinct in young state. Mr Currey regards it as " a 

 true Sphwria. . . . There are certainly thecse filled with very numerous, brown, 

 1-septate sporidia, O - 0003". . . . The perithecia are so minute and so scattered, that 

 it is extremely difficult to detach them for examination." He refers the parasite 

 to S. ventosaria; but the perithecia are very different from those common in 

 the same parasite on Lecanora ventosa. 



IV. Microthelia. 



1. M. Cookei. Parasitic on thallus of Lecanora crenulata, Dicks., Barrack wall, 

 Chichester, W. C. Cooke, March 1866. The parasite occurs on the thicker, 

 whiter portions of the thallus, as black, papillseform, scattered conceptacles. The 

 hymenium gives no blue with iodine ; its constituents are very indistinct, unless 

 under the action of iodine or other colouring matter. Hypothecium is colourless. 

 Paraphyses appear rather like a mass of striated jelly than as distinct, filiform 

 threads— resembling in this respect those of Pertusaria. Apices not coloured 

 Asci polysporous, saccate, bulging irregularly, 0018" long, -00045" broad. Sporidia 

 very small, -00022" long, -00009" broad; colourless; oblong-ellipsoid; 1-septate, 

 sometimes simple. 



M. Cookei externally resembles M. rimosicola of Mudd's Exsic. No. 301 ; 

 but the asci in the latter are 8-spored. It differs from all the Microthelia? men- 

 tioned in Mudd's "Manual of British Lichens," in having colourless sporidia; 

 but in other points it resembles M. pygmoea, Korb., which is also polysporous. 



2. M. Stereocaulicola. Parasitic on thallus of Stereocaulon paschale, L., Glen 

 Derrie, Braemar, Croall, July 1854. 



The free ends of some of the podetia of the Stereocaulon are the seat of 

 bullose-looking deformities or expansions, which are compound solid verruca?, 

 made up of an aggregation of minute wartlets, of the same colour as the normal 



* Transactions of the Royal Society of Edinburgh, vol. xxiv. 

 t Transactions of the Linnean Society, vol. xxvii. (1869). 



VOL. XXV. PART II. 6 Z 



