538 DR LAUDER LINDSAY ON NEW LICHENICOLOUS MICRO-FUNGI. 



podetium and its squamules. These thalline deformities closely resemble those 

 which are occupied by spermogonia in the same Stereocaulon and in S. denudatum, 

 Flk., as they are figured in my " Memoir on Spermogones" (plate v. figs. 33 and 

 36). Moreover, the parasite closely resembles the spermogonia in question in its 

 conceptacles forming brown or black verrucarioid papillae ; sometimes visible as 

 mere points, the body immersed in the wartlets of the thalline deformities of the 

 Stereocaulon — one or two in each wartlet — the apex alone projecting. Asci not 

 blue with iodine, -0023" long, -00066'' broad. No distinct paraphyses. Sporidia, 

 0005" long, -00033" broad ; obovate ; colourless when young, becoming olive or 

 brown with age ; 1-septate. 



Th. Fries* has described, without naming, a Sphwria as parasitic on the thallus 

 of >S'. alpinum, Laur., in Spitzbergen ; whose sporidia, however, distinguish it from 

 the Microthelia. The hymenium of the Sphceria — which may appropriately bear 

 the specific name Stereocaulicola — becomes yellow with iodine. The sporidia are 

 blackish, four in each ascus, oblong-elongate, 3-5-septate, becoming submuri- 

 form by longitudinal division of the loculi. Korber (in his " Parerga," p. 455), 

 describes Scutida Stereocaulorum, Anzi, as parasitic on Stereocaulon alpinum and 

 S. fastigiatum in the Alps of Northern Italy. But its sporidia are smallish, 

 narrowly ellipsoid, subcymbiform, 1-septate, and colourless. Also his Polycoccum 

 Sauteri (" Parerga," p 470) as occurring on the protothallus and thallus of S. con- 

 densatum, Hffm. Sporidia small, dacryoid, 1-septate, brownish. 



One or more species of Sirosiphon (an alga belonging to the family Siro- 

 siphoniacece, of the Palmellaceoe or Protophyta, according to Rabenhorst (Fl. Europ. 

 Algar. Aq. dulcis, &c. p. 289), are parasitic on some species of Stereocaulon. Thus 

 Sirosiphon saxicola, Nteg. (perhaps the S. Crustacea, Ag., of Rabenhorst, op. cit. 

 p. 289), is parasitic on Stereocaulon denudatum in Scandinavia (Nyl. " Scand." 

 p. 65); while a Sirosiphon, not named, and which may be also S. saxicola, grows 

 on the podetia of Stereocaulon vulcani, Bor., and was mistaken for cephalodia by 

 Fries (Nyl. " Lich. Exotic." p. 252). The parasite occurs as blackish pulvinuli, 

 which are quite different in anatomical constitution from cephalodia ; the latter 

 always exhibiting on section the structure of — 1. The cortical; 2. Gonimic ; and 

 3. Medullary, tissues of the lichen-thallus. 



3. M. Umbilicarice. Parasitic on the sterile thallus of Umbilicaria pustulata, 

 Hffm.; collected in Norway as commercial " Pustulatous moss." The parasite is 

 copiously studded over both the bullae and interspaces of the thallus, as black, 

 papillseform conceptacles, varying somewhat in size and form ; semi-immersed ; 

 comparatively conspicuous on the gray, cracked thallus of the host. Paraphyses 

 very delicate and indistinct, as in Verrucaria. Asci very faint violet with iodine; 

 while the hymenial gelatine shows more distinctly the same tint with the same 



* il Lichenes Spitsbergenses," p. 36. Vide also author's " Observations on Greenland 

 Lichens." 



