139 371 
4, Arthonia (Ach.) Wain. 
71. A. (subg. Arthothelium) Ruana Mass., Ric. Aut. Lich. Crost. 
(1852), p. 49; Willey, Syn. Arth. (1890), p.52. A. Ruana Anzi, Lich. 
Exs. It. Sup. (1865), no. 383 (no. 5660 in herb. Nyl.). Dermatina 
Ruana Almqu., Mon. Arth. Scand. (1880), p. 8. 
Thallus tenuis, laevigatus, albidus, continuus, epiphloeodes. Apo- 
thecia rotundata aut difformia confluentiave, aggregata aut approximata, 
long. 0,2—1 mm., latit. 0,2—0,5 mm., disco plano aut depresso-convexo, 
thallum aequante aut leviter superante, primum fragmentis thallinis sparsis 
obducta, dein nuda nigraque. Hypothecium albidum vel pallidum. Hy- 
menium jodo intense persistenter caerulescens, ascis dilute violascentibus. 
Epithecium fusco-fuligineum. Asci obovoidei, parte superiore pachyderma- 
tici, long. circ. 0,060 mm., crass. circ. 0,030 mm. Sporae 8: nae, deco- 
lores, ellipsoideae aut oblongae aut ovoideae, murales, seriebus cellularum 
transversalibus 10—9, jodo leviter vinose rubentes, halone nullo indutae, 
apicibus rotundatis aut altero apice rotundato-obtuso, long. 0,020—0,023, 
crass. 0,009—0,010 mm. 
Ad corticem Rhizophorae prope Stationem navalem Lem Ngob 
(no. XIV). 
Ab hac A. anastomosans (Ach.) Nyl., Lich. Scand., p. 259 (Willey, 
Syn. Arth., p. 53), secund. no. 5640 in herb. Nyl. thallo hypophloeode 
et ,gelatina hymeniali jodo vinose rubente‘ distinguitur. Etiam in speci- 
mine Anziano A. Ruanae (Anzi, |. c. no. 383) hymenium jodo caerule- 
scens. A. abnormis (Ach.) Nyl., Syn. Lich. Nov. Cal., p. 64, Willey, 
Syn. Arth., p. 53 (Mill. Arg., Graph. Féean., p. 60), habitu huice con- 
gruens, observante Nyl. reactione jodetica ab ea differt (no. 5746 in hb. Nyl.). 
Var. phaeospora Wain. 
Sporae demum fuscescentes, long. 0,020—0,024, crass. 0,008— 
0,012 mm., murales, jodo leviter vinose rubentes. Hymenium jodo 
caerulescens. Hypothecium albidum vel pallidum. 
Ad corticem Arecae prope Stationem navalem in insula Koh Chang 
(no. X). 
Area: A. Ruana in Europa et Asia crescit. 
72. A. (subg. Euarthonia) complanata Fée, Ess. Crypt. Ecore. (1824), 
p. 54; Wain., Etud. Lich. Bres. Il (1890), p. 154; Willey, Syn. Arth. 
(1890), p. 40. 
Thallus albidus, opacus, continuus. Apothecia anguloso-rotundata 
aut difformia, long. 1,2—0,3 mm., latit. 0,7—-0,3 mm., crass. cire. 0,080 mm., 
disco nigro, epruinoso, opaco, plano. Hypothecium pallidum. Hymenium 
et hypothecium jodo persistenter caerulescentia. Epithecium fuscescens 
aut olivaceo-fuscescens. Asci subglobosi aut pyriformi-subglobosi, long. 
0,035, crass. 0,030 mm. Sporae 8:nae, decolores, 5-septatae, cellula 
apicis crassioris cellulis medianis triplo longiore, etiam cellula apicis 
tenuioris medianis longiore, long. 0,028—0,025, crass. 0,007—0,008 mm. 
24* 
