Plagiogr aphis. ~\ 
VII. LICHENES. 
589 
flexuose or branched, contracted here and there; thallodal margin very thin, 
at length erect ; epithecium nearly covered by the perithecial walls, dark- 
coloured ; spores contracted in the middle, 1 -septate, upper cell larger, 
0 00030 in. broad, 0’00065 long. 
Northern Island : Auckland, on smooth hark, Knight. — Apothecia externally like black 
pecks. At first sight this resembles an Arthonia. 
2. P. rubrica, Knight and Mitt. 1. c.f. 28. Thallus corneous, polished, 
red or reddish-brown. Apothecia round oblong or elongate and nerved, 
without thallodal border, blackish-brown, slightly prominent, open ; perithe- 
cium extending far below the thallus; spores 1-septate, 0'00020 in. broad, 
0 00053 long. 
Northern Island: Auckland, on smooth bark, Knight. — Similar to P. devia, but diffe- 
rently coloured, and with open apothecia. 
38. STIGMATIDIUM, Meyer. 
Thallus thick, crustaceous or cartilaginous. Warts containing the apothe- 
cia crowded, punctiform, solitary or in series, immersed, indehiscent, without 
a border. 
A small genus of tropical and temperate corticolous Lichens, found in various parts of the 
world. 
1. S. crassum, Du by. Thallus cartilaginous, undulated, olive-brown, 
smooth, black-edged. Warts of the apothecia large, irregular, many-celled, 
with numerous, black, slightly depressed, often confluent and then linear 
curved points. — Nyland. Prodr. Lich. Gall, and Alger. 163. 
Northern Island : on bark, Colenso. (West Europe, N. Africa.) 
39. ARTHONIA, Ach. 
Thallus thin, superficial or beneath the bark, or evanescent or none. Apo- 
thecia flat, without a border, separate paraphyses none ; asci pyriform, easily 
separable from the apothecium ; their walls thickened at the tip ; spores 4-8, 
ovoid, septate. Spermatia cylindric, straight or curved. 
A large genus of Lichens, growing on wood and bark in all latitudes. 
1. A. lurida, Ach . — Myriangium inconspicuum, Bab. in PI. N. Z. ii. 310. 
t. 128 B. Thallus somewhat tartareous, thin, cracked, uneven, white. Apo- 
thecia crowded, immersed, thin, flat, confluent, brownish lead-coloured, prui- 
nose, internally of the same colour; spores ovoid, 1-septate. — Nyland. Lich. 
Scand. 268. 
Northern Island: on dead leaves, Colenso. (Europe.) 
2. A. pruimosa, Ach.—Lecanactis impolita. Fries ; — Bab. in FI. N. Z. ii. 
303. Thallus white, thin, cracked, somewhat uneven. Apothecia immersed, 
flat, confluent, brownish lead-coloured, pruinose, same colour within ; spores 
ovoid, 3-septate. — Nyland. Lich. Scand. 258. 
Northern Island : Auckland, on bark, Knight. (Europe, N. America.) 
