BRITISH LICHENS

APPENDIX 399
scattered or contiguous, roundish or often variously angulose,
somewhat smooth, beneath white (K -, OaCl), the cortex
amorphous, but surmounted by brown capitate hyphre. Apothecia
roundish or oblong, one or sometimes 2-3 in thc areolro,
,15-·2 mm. wide, at first immersed then becoming plane with a
thin thalline margin, thc disc plane, smooth; paraphyses rather
coherent, sub capitate, fuscate; spores oblong, 3-4: !1. long, 1-1·5 !1.
thick; hymenial gelatine blue with iodine.
The original specimen occurrcd on slate on the sand-dunes, :Malo.
In the specimen from·Essex (which was included under A. smaragdula),
the hymenium is rather high (about 200 1-'). Magnusson (in Zitt.)
considers that A. jusca is nearly akin to A. smaragdula and to A.
Lesdainii, perhaps only a variety of either of them.
Another darker specimen on the same mount from Beeleigh, Essex.
he has noted as "uncertain and belonging to the rujescens group.
possibly a new species." The hymenium is not so high (about 80 p.) but
the capitate brown paraphyses are very marked.
Hab. On siliceous stones.-B. M. Near railway bridge, Langford,
Essex.
A. requatuJa Magnusson in Goteb. K. Vet.-och Vitt.-Samh.
Hand!. xxviii. 2, 128 (1924).-Thallus continuous, crackedareolate,
thin or rather thick, dark-reddish-brown, surface on the
whole even, but areolre uneven as if composed of minute squamules
(K -, CaCI -). Apothecia small, one (or few?) in each areola
·2-·5 mm. wide, slightly impressed, becoming plane, concolorous
with the thallus, with an inconspicuous margin; hypothecium
dark-yellowish; paraphyses coherent, slender, the tips wider and
brown (3-4 p. wide); asci abundant; spores 3-4 !1. long, 1'5-2 !1.
thick; hymenium 100-125 !1. high, blue or, in thin section, red
with iodine.
Our specimens had both been determined as Lecanora rujescens, and
were included under A. smaragdula, from which they differ in the
absence of K reaction and in the flattened continuous thallus.
Hab. On siliceous rocks.-B. ],1. DolgeUy, Merioneth; Appin,
Argyll.
A. Muddii Magnusson in Medd. Goteb. Bot. Triidgard ii.
72 (1925).
" Areolro towards the centre globulose-verrucose, very unequal
in size and shape, somewhat widely affixed to the substratum.
Cortical cell-lumina large, 3-6 p. wide, cortical and medullary
hyphre with thin walls. Apothecia 1 to 3 in each areola, impressed,
the disc ,1-,3 mm. wide without a thalline margin;
hymenium 115-125 !1. high, blue or reddish with iodine; paraphyses
brownish-capitate; spores somewhat broadly ellipsoid,
3-4 !1.long, 1·5-1·7 !1. thick (perhaps not well developed)."
This species has so far only been found in Britain: the specimens
were regarded by Mudd as A. cervina var. rujescens, and the difference
between them and other Acarosporre was discovered by Dr. Magnusson
and publishcd in a paper entitled" New or Misunderstood European