PYCNIDES OF CRUSTACEOUS LICHENS. 231 
seated on simple, linear, short sterigmata. Possibly the spermogones in question are 
referable to the associated Lecidea. In both, the sterigmata are simple; but the sper- 
matia of the Lecidea are longer (1555 long), while their breadth is the same. Whether, 
therefore, they are referred to the Lecanora or Lecidea, their character differs from that 
of the type. 
Specimen 3. On coarse sandstone or grit, Ingleby, Cleveland, Yorkshire. Leight. 
Exs. No. 213, sub Biatora rupestris, var. irrubata, Ach., E. Bot. t. 2245 (2062), which 
is certainly, according to its sporidia, a saxicolous form of cerina*. On the whitish 
cushion-like scales of a thallus, which is associated only, and does not apparently belong 
to the Lecanora, are seated minute, black, punctiform spermogones, containing very small 
(almost atomic), oblong or subellipsoid spermatia. Other (separate) scales of the same 
thallus, or, at least, the same kind, bear externally similar pycnides, containing large 
stylospores, borne on long, slender, filiform basidia. 
Species 23. L. CALLOPISMA, Ach. (=Placodium, Hepp & Nyl., Mudd, Brit. Lich. p. 133) : 
which appears to me merely a form of Placodium murorum t, with a more Parmelioid 
thallus. 
Specimen 1. On limestone, Blackrock, Cork, Carroll Mar. 1858. Spermogones are 
bright orange tubercles (not seen unless under moisture and with the aid of the lens, 
and even then inconspicuous), scattered sparingly outside the region of the apothecia, on 
the convexities of the radiating laciniæ. In some respects they resemble those of 
Physcia parietina. Spermatia are rod-shaped, pogo long, and 345-355 to 45.154 broad, in 
great abundance. 
Species 24, L. LEUCOLEPIS, Ach. = Pannaria Hookeri, Sm., Mudd, Brit. Lich. p. 125; 
Parmelia, Fr. & Scheer.; Lichen Hookeri and Squamaria leucolepis, Hook., and E. 
- Bot. 2283 (2120). 
Specimen 1. Ben Lawers, 1808, in Kew herb. Associated with the Lecanora, 1 found 
a Lecidea, having apothecia with a black turgid border, like var. turgida of Lecidea con- 
tigua, and simple ellipsoid sporidia, the thallus being white and frustulose. I had no 
proper opportunity of determining the species; but it was probably an alpine form of the 
protean and ubiquitous L. contigua. A few spermogones were seen, as black points or 
papillæ, immersed or semi-immersed, containing straight spermatia, about 5555 long, 
seated on sterigmata that are 4355 to 305 long, and digitately divided below. Both . 
apothecia and spermogones were conspicuous by reason of the contrast between their 
black colour and the whiteness of the thallus. 
- * Compare also Lecanora calva, var. irrubata, p. 230; and Lecanora pyracea, * Obs. on New Lichenicolous Micro- 
Fungi, p. 549. Crombie, in his * Lichenes Britannici? (1870), p. 47, following Nylander, makes separate species of 
L. cerina, L, pyracea, and L. calva, They appear to me, however, to pass into each other by gradations of such a 
character that different specimens of Leighton's Exs. No. 213 have been referred, both by other authors and myself, 
at different times, sometimes to the one, sometimes to the other, of these three so-called species ! 
t Compare my first Mem. Spermog., plate xv. figs. 1, 2, and p. 267. + Ibid. plate xiv. fig. 1. 
2K 2 
