466 
Proceedings of the Royal Society 
Dirina immersa, Mull. Arg. f. sorediata, Mull. Arg. : thallus 
sterilis, minute sorediosus. — Cum forma genuina speciei, calcicola : 
B.C.S. 
Opegrapha (sect. Lecanaetis ) vestita, Mull. Arg. : thallus albus, 
tenuis, levigatus, nitidulus ; apothecia primum orbicularia, dein 
1-1J mm. longa et varie oblongata, simplicia v. altero latere 
uniramea, sessilia, late adnata, primum undique crasse thallino- 
vestita, margines proprii lecideini dein emergentes et minus conni- 
ventes, discus crasse albido-pruinosus ; sporse octonse, 20-28 g 
longse, 6-7 g latse, fusiformes, 8-loculares. — Lignicola : B.C.S. 
Opegrapha (sect. Lecanaetis) elegans, Mull. Arg. : similis 0. 
lyncece , a qua differt thallo albiore, apotlieciis multo gracilioribus 
et sporis brevioribus, 18-27 g longis, absque lialone 4 g latis, 7-8 
septatis. — Lignicola : B.C.S. 
Opegrapha (sect. Lecanaetis) subcalcarea, Mull. Arg. : thallus 
tartareus, crassiusculus, continuus et levigatus, virescenti-albus, 
intus cretaceo-albus ; apothecia \ mm. lata et regulariter orbicu- 
laria, demum radiatim abbreviato 2-3-ramulosa, omnino immersa, 
csesio-pruinosa, demum nigricantia; sporse 20-25 g. longie, 5 g 
latse, dactyloidese, 4-6-loculares. — Calcicola : B.C.S. 
Opegrapha (sect. Lecanaetis) cretacea, Mull. Arg. : thallus 
crassiusculus, supra subfarinosus, continuus, junior levigatus, 
cretaceo-albus ; apothecia primum innata, orbicularia, pruinosa, 
dein subinnato-sessilia, mox angulosa et reniformia v. abbreviatim 
lobulata, discus planus, csesio-velatus, margo acute prominens et 
niger, latere extus albo-farinulentus ; sporse 30-34 g longse, 4-5 g 
latse, dactyloidese., 7-9 septatse. — Calcicola : B.C.S. 
Opegrapha Drac^enar™, Miill. Ar. \g thallus tenuis, albus, levis, 
demum rugulosus ; apothecia d mm. lata, pluries longiora quam 
lata, elongata et varie flexuoso-curvata, primum plane innata, thallo 
tecta, demum denudata, sed non emersa, atra, opaca, rima angusta 
depressa albo-pruinosa, demum atrata, margines angusti haud 
sulcati ; hypothecium fuscum ; sporse 15 g longse, 4 g latse, fusi- 
formes, 4-5-loculares. — In ramis Dracsenarum : Schweinf 
