LICHENS AND LICHEN. PARASITES

DODGE-LICHENS AND LICHEN PARASITES
Sqnatrla~ia subg. Sqziu.rnuria Boist., Nouv. F1. Lich., 2, 89; 1903.
Zeora sect. Pla,codes Fw., Jahresber. Schles. Ges. Taterl. Iiultur, 27, 121 ; 1849.
Psorodiunt Trev., Riv. Period. Lav. I. R. Accad. Paclova, 256; 1851-2.
Placodizbnt subg. Spntiplncodl'unt Boiet., Nouv. b'l. Lich., 2, 97; 1903.
Parntzdaria. B. Nils in IIumb., Naturw. Unters. Sarelrgebirg. Schwed. Lappl., 3, 34; 1907 : non
Lev., Ann. Sci. Nat. Bot. 111, 3, 5, 236; 1846.
Lecanora sect. Parntu!uria Hue, Ann. Myc., 12, 520; 1914.
Placolecanora Ras., Jour. Jap. Rot., 16, 90; 1940.
Type: as some of the above cited literature is uiiavailable to me, wc may defer the consi.dera-
tion of a type until a later paper.
Thallus crustose i11 the centre, margin determinate, lobed to squamose, without rhizinae;
corticate above, ecorticate below; apothecia sessile or stallred, amphithecium present, parathecium
variable in development.
LECANORA EXSULANS (Th. Fries) Dodge & Baker.
Lecano~.a exsulans (Th. Fries) Dodge & Baker, Ann. hfo. Bot. Card., 25, 570; 1938.
Lecanora cltryso!ezcca (Smith) Ach., var. mela~iophthalnta (Ram.) Th. Fries, f. exsulans Th. Fries,
Nyt. Mag. Naturvidensk., 40, 208; 1902.
Lecanora rdina (Vill.) Ach., var. me!anopltthalnta (Ram.) Zahlbr. f. exsu!ans (Th. Fries)
Zahlbr., Cat. Lich. Univ., 5, 660; 1928.
Type: South Victoria Land, Geikie Land, 71" 40' S., 170' E., 100 m., C. E. Borchgrevink
(in Oslo and Upsala).
Thallus pulvinate, cerebriform masses 1.5-2 cm. in diameter, 3-5 mm. tall, rather fragile,
apothecial stalks somewhat branching near the base, mostly smooth, sometimes slightly verrucose
(from incipient spermogonia and apothecia ? ) , margin crenate, soon concealed by developing
apothecia, light ochraceous salmon to light ochraceous buff; cortex subfastigiate, of slender,
hyaline hyphae, about 3p in diameter, branched and anastomosing in a gel, tips decomposed and
covered with millute arystals, about 60p thick, less regular and decomposed below, where the
algal layer is absent; algal layer about 35p thick, of discrete colonies, cells 7-8p in diameter,
protococc~id ; medulla compact, of slender, branched, interwove11 hyphae, enclosing many rock
crystals.
Apothecia 2-3 mm. in diamter, disc slightly concave at first, light ochraceous buff, sooii
plane then convex to hemispheric, covering the whole of the apothecial stallr. nickel green and
finally dusky green, almost black, margin smooth becoming crenulate and irregular, finally
disappearing, sometimes coilcrescent in cerebriform masses; amphithecium not differentiated
from the tissues of the apothecial stklk; parathecium 75p thick below, thinning to about 30p at
the margin, of slender, densely woven, hyaline hyphae, continuous with the medulla in the centre
and between the algal colonies which are better developed, often reaching 75p in diameter and
form a nearly continuous layer below the parathecium; hypothecium about 35p thick, of subvertical,
closely septate, slender, deeply staining hyphae ; thecium 50p tall ; paraphyses slender.
little branched, the last 6-8 cells spherical, about lp in diameter, epithecial gei not coloured ir
thin sections; asci clavate, tips thickened, protoplasts truncate, long mamillate 35-40 x 7-8p
ascospores long ellipsoid, unicellular, hyaline, 12-15 X 4p when still in the ascus 8-10 X 3p witk
thick epispore when discharged.