BRITISH LICHENS

LECIDEA LECIDEACELE 77
In the Br;tish specimens the thallus is either rather scattered (form
dispersa Arnold III Flora h. 35 (1868)), or more commonly scarcely
visible. The apothecia are rather variable, being frequently, as
Schrerer says, minute and several aggregate with a common exciple.
TIns, as in other cases, is owing to the growth of young fruit upon
the old.
Hab. On calcareous rocks in hIlly and mountainous districts.­
Distr. Seen from only a few locahties III W. and Central England, N.
Wales and the Grampians, Scotland.-B.ll:l. Bathampton Downs,
Somerset; Black Dale, near Buxton, Derbyshire; Lyn Cae, Cader
Idris, Merioneth; Cunswick Scar, Whitbarrow and Mallerstang, West·
morland; Achosragan Hill, Appin, Argyll; Craig Tulloch, Blair
Athole, Perthshire; Morrone, Braemar, Aberdeenshire.
135. L. subumbonella Lamy in Bull. Soc. Bot. Fr. xxx. 409
(1883).-Thallus effuse, thinnish, unequal, white, subopaque
(K -, CaCI-). Apothecia minute or subminute, somewhat
plane, margined, umbonate in the centre, black, opaque; hypothecium
thickish, brown; paraphyses sub coherent, pale-brown
at the apices; spores oblong-ellipsoid, 16-22 [! long, 7-9 [l. thick;
hymenial gelatine bluish, the asci at length tawny-wine-red,
with lOdine.-L. subumbonata Nyl. in Flora lix. 236 (1876), non
in Flora Iv. 358 (1872); Cromb. in Grevillea v. 28; Leight. Lich.
Fl. ed. 3, 306.
Exs!cc. Johns. n. 42\).
Tho apothecia, frequent in the specimens from Ireland, often appear
as if divided into several hymenia. The spermogones, sparmgly
present, have the spermatia cylindrical, or fusiform-cylindrical, 4-7 [l.
long, 0·8 [l. thick. Johnson's speClmen from Cumberland has a somewhat
thicker areolate thallus, and the apothecia arc occasionally
aggregate.
Hab. On mica-schist rocks in upland situations.-B. M. Wastdale,
Cumberland; near Letterfrack, Connemara, Galway.
136. L. contortula Stirton in Scott. Nat. iv. 167 (1877).­
Thallus pale or leaden-grey, thickish, somewhat wrinkled, rimoseareolate
(K -, CaCI -). Apothecia black, adnate, rather large,
plane or somewhat convex, umbonate or gyrose-plicate, with a
thlCk margin; hypothecium brownIsh-black, brownish upwards;
paraphyses distinct, brown at the apices; spores oblong or fusiform
oblong, 15-21 [l. long, 6-7'5 fL broad, hymenial gelatine blue
then wine-red with iodine.-Leight. Lich. Fl. ed. 3, 307.
Stirton considered his species as allied to L. 81lbumbonella, but in
L. contortula the paraphyses are slender and distmct and bright
olivaceous-green to brown at the apices. The gyrose character as in
L. jurana is due to the inclusion of several small apothecia of varying
stages of development within a rather flexuose common exciple_
Johnson's specimen from Bywell is more akin to L. contigua var.
platycarpa.
Hub. On rocks.-B. M. Near Salen, I. of Mull, Argyll.