414 DR LAUDER LINDSAY ON THE 



very small, and very closely aggregated. I did not succeed, under power 425 of 

 my Nachet's microscope (£-inch objective), in distinguishing the spores, which 

 are also very small. 



12. Lecanora homologa, Nyl., Licb. N.Z., 251 (figs. 13, 14). 



On the trunks of living trees, Greenisland Bush : associated with Physcia 

 plinthiza, Nyl. 



It has a general close resemblance to some forms of L. subfusca, Ach. ; but its 

 spores (fig. 14) at once distinguish it. These are broadly ellipsoid or oblong, 

 colourless; sometimes convex on one side, and straight on the other (plano- 

 convex); 1-septate, and constricted (c) or not at the septum (in the old state); -0009' 

 long, and 00045" broad. In the young state they are occasionally polari-bilocular 

 (a); or there are three loculi (5), (the central one by far the largest), round, oval, 

 sub-angular or quadrilateral, united generally by a tubule running up the centre of 

 the spore as a kind of longitudinal canal. Very commonly they are 3-locular, with 

 loculi resembling those of the spores of Verrucaria nitida, Schrad. 



The thecw (fig. 13 b) are large, distinct, and ventricose; 8-spored; -0036" to 

 0045" long, and -0012" broad ; beautifully blue under iodine, as are also the hymenial 

 lichenine generally, and the tips of the paraphyses (a). The paraphyses are very 

 delicate, filiform, colourless, indistinct, devoid of clavate or coloured heads. 



13. L.peloleuca, Nyl, Lick N.Z., 251 (fig. 15). 

 On columnar basalt, Greenisland Bluff. 



The paraphyses are delicate and indistinct, without coloured, clavate heads. 

 The thecce are closely aggregated, of medium size, deep blue with iodine. The 

 spores (fig. 15) are broadly ellipsoid or oval; of various shades of olive or brown, 

 according to age ; being deepest brown in the old state (c), palest olive in the 

 young (a); -00075" long, and -00045" broad : in the young state polari-bilocular (a), 

 the loculi sometimes connected by a median longitudinal tubule or canal : in 

 the old state 1-septate {b), with a constriction or not opposite the septum, some- 

 times having the figure of 8-form of (c), and otherwise resembling, the spores of 

 Physcia pulverulenta, Fr. 



14. L. thiomela, Nyl., Lich. N.Z., 252 (fig. 16). 

 On basaltic porphyry, Forbury Heads, Dunedin. 



The thecse and spores are best seen in young apothecia, which have much the 

 aspect of spermogones, being yellow papillae, perforated apparently by a darker, 

 brownish-yellow ostiole, which is, however, the unexposed and unexpanded disk. 

 The paraphyses are delicate, filiform, indistinct, without coloured, clavate heads. 

 The hymenial gelatine gives a beautiful dark-blue colour with iodine. The thecw 



