104 KNIGHT AND MITTEN ON NEW ZEALAND LICHENS. 
P. occulta, K. & M. Thallus reddish-brown, obscure, apothecia irregularly branched, 
subradiate, angular, edges torn ; thallodal margin raised, powdery white ; epithecium 
flat, blackish-brown; hypothecium black; spores fastigiate, fusiform, 4?-septate> 
measuring from 0-00005 to 0*00160 of an inch 
Hah 
Thallus very obscure, scarcely evident, and apothecia quite imperceptible to the naked 
eye. This species agrees with the preceding ones in the arrangement of its spores. 
Pl. XII. fig. 26. a. section of thallus and apothecium; b. theca; c. spore; d. apothecium as seen from above. 
Plagiographis, new genus. 
Thallus very thin, obscure (hypophleode ?) ; apothecia elongate rimaeform, surrounded by a perithecium 
which is covered by the thallus, connivent above, and divaricated and oblique below ; hypothecium free ; 
thecse pyriform ; spores bilocular. 
P. devia, K. & M. Thallus smooth, thin, yellow or grey ; apothecia blackish brown, 
elongate, flexuose or branched, here and there contracted, thallodal margin very 
thin, at length erect ; epithecium nearly covered by the walls of the perithecium, 
dark-coloured; spores contracted in the middle, 1-septate, upper cell the larger, 
measuring from 0*00030 to 0*00065 of an inch. 
Hub. On smooth bark, Auckland. 
Apothecia externally like small black specks ; when magnified, they appear as long or 
short almost closed lirellse ; on making a vertical section, they are seen to have on each 
side a black wall of perithecium immediately beneath the surface of the thallus, extending 
a considerable distance in its substance away from the epithecium, and leaving the lower 
part of the thalamium and its base entirely free. At first sight, the appearance of this 
species is entirely that of an Arthonia. 
Pl. XII. fig. 27. a. section of thallus and apothecia; b. thecae; c. spores. 
P. rubric A, K. & M. Thallus corneous, polished, red or reddish brown ; apothecium 
round, oblong, or elongate and curved, without any thallodal margin, blackish-brown, 
slightly prominent, open ; perithecium extending far under the thallus ; spores 1-sep- 
tate, measuring from 0*00020 to 0*00053 of an inch. 
Hab. On smooth bark, Auckland. 
Similar to the preceding species, but with a differently coloured thallus and open apo- 
thecia, which in a vertical section exhibit the dark-brown perithecial walls extending far 
under the thallus on each side, and, as in the other species, leaving the lower part of the 
thalamium entirely free. 
Pl. XII. fig. 28. a. section of the thallus and apothecium, with a portion of the bark beneath; b. thecae 
and spores ; c. apothecium as seen from above. 
Arthonia, Ach 
A. lobulata, K. &M. Thallus ochreous or grey; apothecia angular, lobed or subradiate 
