LICHENS AND LICHEN. PARASITES

DODGE-LICHENS AND LICHEN PARASITES 175
especially below the hypothecium; paraphyses slender; asci clavate to cylindric, thin-walled.
8-spored; ascospores unicellular, hyaline, thin-walled.
This endemic genus with its large, conspicuous innate apotheca and large floriforin cephalodia
is easily recognized.
ASPICILIOPSIS MACROPIITHALMA (Hook. f. & Tayl.) Dodge, comb, nov.
Urceolaria naacropAtha.Lnza Hook. f. & Tayl., London Jour. Bot. 3, 640; 1844.
Lecanora gelida Bab. ap. Ho&. f., Cryptog. Antarct., 229, 1845 : F1. Antarct., 2, 535 ; 1847 p.p. 11011
(L.) Ach.
Lccanora macrqphthalma Nyl., M@m, Soc. I. Sci. Nat. Cherbourg, 5, 336 ; 1857 : Flora 41,489 ; 1858 :
~uck., Bull. Torrey Bot. Club, 6,58 ; 1875 : Bull. U.S. Nat. AILIS., 3, 29 ; 1876 : Crombie, Jour.
Linn. Soc. Bot., 15, 185 ; 1876 : Jour. Bot. Brit. For., 15, 104; 1877 : Phil. Trans. Roy. Soc.
[London], 168, 48; 1879 : Rept. Sci. Results Voy. "Challeilger" Bot., 1, 2, 234; 1885 : Zahlbr.,
Deutsche Siidpolar Exp., 8,48 ; 1906.
Placopsis macrophthadma, Nyl. ap. Crombie, Jour. Bot. Brit. For., 15,106; 1877.
Placodium ntacrophthalmz~m Miill.-Arg., Bot. Jahrb. [Engler] , 5, 135 ; 1884 : Forschungsreise
S. M. S. "Gazelle," 4, 10 ; 1889 : Wilson, hIbm. Herb. Boissier, 18, 87 ; 1900.
Type : Kerguelen, Christmas Harbour, J. D. Hooker (Voy. "Erebus & Terror").
Thallus thick, up to 1 mm., emooth, centre irregularly cracked through the algal layer, and
attached to the substrate by rhizinoid hyphae, especially in older thalli, margin determinate ,more
or less lobed and free from the substrate, olive buff to pale olive buff; upper cortex pseudoparenchymatous,
10-15p thick, protoplasts spherical, about 2p in diameter ; lower cortex completely
gelified, 10-15p thick, except where the rhiziiioid hyphae pass through to attach the thallus to the
rock; algal layer 220p thick, protococcoid, cells 8-14p i11 diameter, but often replaced by Stigonenta ;
medulla 300~ thiclr but quite variable in thickness, of very slender, thick-walled, conglutinate
hyphae, mostly vertical; cephalodia scattered over the central portion, circular to floriform, up to
8 mm. in diameter, slightly elevated, radially cracked, vinaceous fawn to the colour of the thallus,
algae Stigonema. Apothecia immersed, aspicilioid, 1-1.7 mm. in diameter, disc slightly concave
to plane, pruinose, becoming black; amphithecium not differentiated; parathecium 3 5 thick, ~ of
hyaline. thin-walled hyphae, 3p in diameter, becoming brownish under the hypothecium, where it
is sometimes 35p thick and blackened, almost carbonaceous; hypothecium up to 150p thick, of
thick-walled dichotomous hyphae, densely woven, subvertical and more deeply staining : thecium
150-180p tall ; paraphyses slender, occasionally branched and anastomosing,,several times dichotomously
branched and somewhat thicker above the tops of the asci and more closely septate,
becoming moniliform, cutting off at the tips short ellipsoidal cells 3-4 X 2-3p; asci cylindric,
120-125p long, wall uniformly 3-4p thick, not conspicuously thickened at the tips, 8-spored;
ascospores monostichous, thin-walled, ellipsoidal hyaline, unicellular, 16-27 X 9-15p. Spermogonia
immersed, ellipsoidal, 275p tall, 150p in diameter, ostiole minute, wall hyaline, about 20p
thick, scarcely differentiated from the medulla except more deeply staining; spermatiophores
slender, lageniform, subulate, 10-12 X 1-1.5~; spermatia very long, slender, 40-60 X lp.
On rocks with Verrucan'a obfuscata, V. tessellatula, V. Werthi;, Cuccotrem kerguelemis,
Encephalograpl~a cerebrinella, Ionaspis kerguelensis, Steinera glaucella, S. Werthii, Leprocollema
obscurius, Lecidea asbolodes, L. Auberti, L. intersita, L. kerguelensis, L. phaeostonta, Mykoblastus
perustus, M. stepha.?todes, Toninia kerguelensis, Urceolina kerguelensis, Pertusana cineraria,
P. ochrolechioides, Huea diphyella, Buellia. subplicata and B. tristitucula*.