DR LAUDER LINDSAY ON NEW LICHENICOLOUS MICRO-FUNGI. 549 



long, and -0004" broad. The Lecidea itself (in my copy, original edition, 1847) 

 has simple, ellipsoid, colourless sporidia; while those of the true L. Hookeri, 

 according to Nylander (Prod. p. 139), are brown and 1-septate. 



18. On thallus of Lecidea sanguinaria, Ach., var. affinis, Schser. (Exsic. No. 

 629, on left hand specimen in my copy, orig. ed. 1852). Intermixed with the 

 spermogonia, and indistinguishable therefrom ; but the parasitic perithecia con- 

 tain round, brown spores. 



19. On thalline scales of Lecanora coarctata, Ach., var. involuta, Tayl. (sub- 

 nom. L. involuta, Tayl., Fl. Hibern., p. 134); Dunkerron, Taylor in Herb. Moore.; 

 on grey sandstone ; associated with L. varia. Parasite occurs as minute black 

 cones, externally resembling spermogonia, but exhibiting no reproductive structure. 



20. On thallus of an isidioid form of Lecanora pa/rella, Ach. (sub-nom. Lichen 

 dactylinus, Ach.), collected by Dr Scott, 1802 ; in Herb. Kew, where it was ex- 

 amined by Dawson Turner. Associated with spermogonia, and externally 

 resembling them. Parasite is black and discoid ; immersed, and bursting through 

 cortical layer of thallus of host. 



21. On thallus of Verrucaria Garovaglii, Mont, (sub-nom. Thelotrema Schcereri) 

 Hepp, Exsic. No. 100 ; which I regard as a mere form of V. pallida, Ach. Parasite 

 may be externally confounded either with the sporidiiferous perithecia or spermo- 

 gonia of the Verrucaria ; but its sporidia are oblong-ovoid, colourless, and 1- 

 septate. 



22. On thallus of Grayhis scripta, Ach., var. horlzontalis, Leight. Exsic. No 

 244 (sub-nom. G. serpentina, var.) ; Abdon, Shropshire. Intermixed with apo- 

 thecia and pycnidia, and externally resembling the latter; occurring here and 

 there as minute black cones, full of minute brown spherical sporidia. 



23. Associated with Opegrapha atra, Pers., var., and Lecidea canescens. Aghada; 

 corticolous ; Carroll. Possesses no distinct paraphyses. Sporidia simple, pale 

 brown, -00066'' long, -00033'' broad— contained in asci. 



24. Associated with Lecanora pyracea, Ach. (sub-nom. Biatora rupestris, var. 

 irrubata) in Leighton's Exsic. No. 213, are conceptacles externally resembling 

 pycnidia or spermogonia, which contain not only stylospores but sporidiiferous 

 asci ; in which, further, the stylospores and sporidia have the same characters 

 The perithecia occur as small, brown, punctiform bodies seated on the thalline scales 

 of the Lecanora. Stylospores are oblong-ellipsoid— normally 1-septate; granular 

 or occupied by two or more nuclear globules or cellules in the young and older 

 states; borne on long, filiform basidia. Sporidia also 1-septate, and having 

 otherwise precisely the characters of the stylospores ; asci 8-spored. There is no 

 possibility of confounding the internal structure of what appears to be a fungus 

 with that of the ordinary spermogonia of the Lecanora, which possess arthro- 

 sterigmata, and very short rod-shaped spermatia. The existence in this fungus of 

 stylospores and sporidia within the same perithecium — springing from the same 



VOL. XXV. PART II. 7C 



