PYCNIDES OF CRUSTACEOUS LICHENS. 255 
3000 X 35:00 On sterigmata which are either short and simple or composed of few 
articulations. 
The character of the spermatia and sterigmata thus differs markedly in the two cases ; 
but it differs, moreover, from that of the spermogones of L. decolorans given by both 
Tulasne and Nylander. The former (Mém. p. 191) describes the spermatia as long and 
curved; the latter (Prod. p. 111) asserts that the sterigmata are simple, the spermatia 
being straight, about 45455 to 5555 X 350500 Nylander suggests that Tulasne mistook 
L. decolorans for L. parasema. But it is quite as plausible to suppose that L. decolorans 
is one of those Lecidee which have plurality of form in their spermogones ; in which case 
Tulasne, Nylander, and myself may be equally correct in our observations ! 
Species 22. L. FLEXUOSA, Fr. (which seems to me to be inseparable as a species from the 
preceding). 
Specimen 1. On trees, Caerlaverock road, Dumfries, Aug. 1856: W. L. L.; with apo- 
thecia. Two forms of spermogone occur, externally undistinguishable, both being black 
and punctiform, sparingly distributed, crowning separate, grey thalline wartlets. The 
one contains atomic oval or ellipsoid spermatia, 15555 long, exhibiting very vivid 
Brownian movement, on simple, sublinear sterigmata, which are broader below; the 
other has rod-shaped spermatia, about ¿255 long, borne on sterigmata that are either 
digitately divided below, as in Abrothallus oxysporus, or compound and articulated. In 
the latter form the basal cellular tissue is brown; and delicate filaments, sterile and 
hypertrophied, project into the spermogonal cavity beyond the ordinary fertile sterigmata, 
as in Ramalina and other genera. | 
Species 23. L. ULIGINOSa, Ach. 
Specimen 1. On peaty soil, Gainsborough Moor, Cleveland: Mudd, 1857. The plant 
here eonsists of spermogones only, and would therefore have been classed by authors of 
the pree-microscope era in the genus Pyrenothea. "These spermogones are with difficulty 
recognizable on the dark-brown earth, unless by patient examination by the lens after 
they have been rendered turgid by moisture. They closely resemble the apothecia in 
external appearance, being superficial and subglobose. But on close examination they 
are found to be minute black perithecia, like those of a Verrucaria or Spheria. Their 
walls are a dark-brown tissue of roundish cellules compactly aggregated; the sper- 
matia are in myriads, 5355 long, oblong, or subellipsoid, borne on the apex of very short, 
inconspicuous, simple sterigmata. Inasmuch as no apothecia are present by whose 
sporidia to determine the species, it is open to doubt whether the spermogones now 
described do not belong to the terricolous form of Z. milliaria, Fr. The varieties or 
forms designated by German authors botryosa, humosa, icinalea and cenosa (Körber, Syst. 
Lich. Germanis, p. 198), probably wholly, or in great measure, are spermogoniferous 
conditions, in which apothecia are either rare, or altogether absent as in the form above 
mentioned. Körber describes the spermatia of var. fuliginea, Ach., as crescent-shaped or 
curved (op. cit. p. 198). 
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