550 DR. LINDSAY ON NEW-ZEALAND LICHENS. 
Sp. 13. L. PETRÆA, Flot. (Fig. 21.) 
On mica-slate, Glen Martin, Chain-hills, Otago: W. L. L. Has somewhat the facies 
of L. fusco-atra. Under moisture, many of the thalline scales or areolz assume a green 
or yellow tint—the character of the thallus of Z. geographica, Spores variable in size 
and form, generally oblong-ellipsoid, muriform, dark brown, -0012” long, :00045" broad; 
in the young state the colour is usually olive, and the spore-outline regular, with a 
symmetrical form ; in the old state there are generally bulgings of the epispore opposite 
the muriform or divided loculi or nuclei, and the form becomes frequently irregular, 
sometimes elongated and pyriform. Thecæ and paraphyses very indistinct. 
L. geographica occurs on basaltic blocks, Signal-hill, North-east Valley, Dunedin; on 
slaty trap and trap conglomerate, Ferry Bluff, Clutha ferry; and it is abundant on 
gneiss and mica-slate on the Tuapeka ranges. 
Sp. 14. L. PARASEMA, Ach. (Fig. 22.) 
a. Corticolous. On trunks of living trees, Greenisland bush. Indistinguishable in 
external characters from L. grossa, L. marginiflexa, and other corticolous Lecidee 
more or less common in Otago ; but at once separated by its spores, which are simple, 
oblong-ellipsoid, colourless, margined in maturity, 00045" to 0006" long, -00025” broad. 
Thecæ 8-spored, :0086" long, 00045” broad. Paraphyses indistinct, tips dark brown, 
granular Hymenium blue with iodine. 
b. Saxicolous. On mica-slate, Glen Martin, Chain-hills; on tertiary grits and con- 
glomerates, base of Saddle-hill. Passes gradually into var. latypea, Ach. Thallus gra 
nulous. Apothecia frequently turgid and subspherical, or lobulate, or tuberculated ; 
when old and subspherical they sometimes fall away, leaving a whitish saucer-like scar 
or hollow of the thallus; frequently crowded, sometimes confluent, marginate in the 
flat normal condition of the disk, immarginate in the subspherical and difform we 
ditions; marginate forms often subangulous from mutual pressure; sometimes white 
pruinose; margin usually very thin and evanescent, sometimes crenulate or irregular. 
Var. latypea, Ach. (Fig. 23.) 
Saxicolous : on mica-slate, Glen Martin; on tertiary grits and conglomerates, Dow of 
Saddle-hill ; on basaltie boulders, top of Kaikorai Hill (associated with Parmelia cone 
spersa &c.); on basaltic porphyry, Forbury cliffs (associated with Lecanora thiomel®s 
Nyl. L. N. Z. 252; Linds. Obs. Otago Lich. and Fungi, p. 414, plate xxix. fig. 16), dés 
W.L.L. Not unfrequently associated with, and passing into, the type or other forms 
L. parasema. 
Spores oblong-ellipsoid, sometimes exhibiting variations in form (subpyriform, per 
convex, slightly curved as in Ramalina), simple, colourless, margined in maturity 
00045” to “0006” long, 00025” to -00045” broad. Thecæ 8-spored, -0018” to 0030" 10% 
0006" to 00075” broad. Paraphyses subdiscrete, filiform ; tips loosely united, b 
brown, granular. Hymenium, including the thecæ, deep blue with iodine. Sperm 
occur on one specimen—mostly, however, old and degenerate, as minute black ue 
resembling some of the smallest species of Verrucaria or Microthelia, seated 0P a 
