546 DR. LINDSAY ON NEW-ZEALAND LICHENS. 
grossa ; colour always black ; they often become convex, immarginate, and difform. The 
hymenium (a, d) gives a beautiful blue with iodine, the coloration extending from the tips 
of the paraphyses to their base, and including the hymenial lichenine, and all the con- 
stituents of the hymenium, Occasionally, however, the coloration in question is very 
slight, and is much less extensive or general. Sometimes the hymenium contains 
immense quantities of oil-globules of all sizes. Paraphyses (a) discrete, filiform, with large 
tuberculated heads, consisting of one or more subspherical or irregular superimposed 
cellules, full of granular blackish-brown colouring-matter ; tips loosely aggregated; 
shape (but not colour) resembles that in some forms of Physcia parietina. The para- 
physes are here unusually (for the genus Zecidea) distinct and easily studied. Thecæ (b) 
8-spored, 0024" to 0030” long, *0006" broad. Spores (e, f) linear or acicular, delicate, 
and frequently indistinct, apt, when their septa are not distinct, to be confounded with 
the bodies or filaments of the paraphyses; colourless, polyseptate (frequently 8-10 
septa), 0015” to 0021” long, ‘00008" to 00010” broad. 
On one specimen, associated with Thelotrema lepadinum, spermogones occur as 
minute, black, punctiform conceptacles, seated on white thalline wartlets, external to 
the region occupied by the apothecia, which are degenerate (exhibiting no spores). 
Spermatia linear, straight, "00015" long, 00006” broad, seated on short simple ste- 
rigmata (g) about 00015” long. 
Sp. 5. L. PULVEREA, Borr., var. Laurocerasi, Del. (Figs. 8,9.) [Nyl. L. N. Z. 255.] 
On trees, Stoney-hill bush; Martin’s bush, Chain-hills, Otago : W. L. L.: associated 
with Verrucaria nitida and other corticolous lichens. The apothecia are extremely 
variable, especially as to colour and form; they bear a general resemblance to those of 
the New Zealand Z. melanotropa, Nyl. (L. N. Z. 255; Linds. Obs. Otago Lich. and Fungi, 
p. 412, plate xxix. fig. 10), and of the British Z. carneola, Ach. (Lichen corneus, Sm. E. Bot. 
t. 965). In Z. pulverea, var. Lawrocerasi, the apothecia generally remain marginate - 
their normal though old condition; the disk is always darker than the margin, which 15 
generally somewhat rugulose or crenulate, and subinvolute on the disk ; sometimes the 
disk becomes turgid. Both disk and exciple have generally a waxy aspect ; under 
moisture this appearance is rendered more distinct, and a semitranslucent or horn-like 
condition is frequently produced. Even in the same apothecium or specimen, and still 
more in different specimens, the apothecia present different shades and combinations of 
brown and black, the former predominating, the disk and its margins possessing ed 
rally different tints. "These tints, especially the browner ones, are rendered more dis- 
tinct by moisture, which causes the apothecia frequently to swell into prownish-yellow, 
subspherical, semitranslucent masses resembling dried beads of gelatine. 
Even without moisture the apothecia occasionally assume such an appearance, when 
they become difform and degenerate; in these cases the hymenium gives à beau fi 
blue reaction: with iodine, but shows no distinction of thecæ, spores, OT paraphyses. 
normal apothecia the hymenium also gives a fine blue colour with iodine. Paraphys® 
subdiscrete, filiform, with dark-brown, granular, thickened but not tuberculiform ups 
Thecæ 8-spored, 0030” long, 0006" broad. Spores linear or acicular, with the character? 
