HEMATOMMA | LECANORACE® 355 
Johns. n. 239; Larb. Lich. Hb. n. 539; Leight. n. 214; Mudd 
n. 130. 
The spores according to Harmand (Lich. Fr. p. 1097) attain a 
length of 70 », in our specimen they are generally about 40 p» long. 
The brightly-coloured apothecia contrast strongly with the white 
or yellowish thallus, which spreads widely on rocks and boulders. 
On tree-trunks, where it occurs occasionally (in the New Forest, 
Dorset and Suffolk), it is always sterile in our country. The recorded 
forms or varieties seem to be simply growth stages. The spermo- 
gones, according to Crombie (Monogr. i. p. 455), are minute and look 
like young apothecia with which they are concolorous. I have been 
unable to verify this. 
The purple reaction of the hymenium with potash is due to the 
presence of hymenorhodin (Zopf, Flechten Stoffe, p. 320) ; it belongs 
to the same group of acid products as parietin. 
Hab. On shaded perpendicular rocks and boulders, rarely on trees, 
in maritime and upland districts.— Distr. Not uncommon throughout 
the British Isles.—B. M. La Coupe and Rozel, Jersey; Guernsey ; 
Brechou ; Alderney ; near Penzance, Cornwall; Ardingly and With- 
yam, Sussex; Beeleigh Abbey, Essex; Stonehenge, Wilts; Malvern, 
Worcestershire; Acton Burnell and Nesscliff Hill, Shropshire ; 
Breiddon Hill, Montgomeryshire; Barmouth, Merioneth; Nant 
Francon and Carnedd Dafydd, Carnarvonshire ; Battersby, Cleveland, 
Yorkshire; Egglestone, Durham; Harlaw Hill, Northumberland; 
Cumberland; West Kilbride, Ayrshire; Roslin, near Edinburgh ; 
Airds, Appin, Argyll; Bowling Bay, Dumbartonshire ; West Water, 
Fife ; Blaeberry Hill near Perth, The Trossachs and Craig Calliach, 
Perthshire ; Portlethen, Kincardineshire; Will’s Braes, Forfarshire ; 
Morrone, Braemar, Aberdeenshire ; Glen Nevis, Invernessshire; near 
Belfast, Antrim; Western Blasquet Island, Kerry. 
3. H. elatinum Koerb. Syst. Lich. Germ. p. 153 (1855).— 
Thallus effuse, thin, granular-furfuraceous, whitish or pale- 
yellowish-white (K + yellow). Apothecia rather small, scattered, 
the disc plane, then convex, light brownish-red, the thalline 
margin thin, soon disappearing ; paraphyses subdiscrete, slender, 
indistinctly septate, sometimes branched, slightly clavate, the 
epithecium of brownish-yellow granules ; spores elongate-fusiform, 
3—5-septate, usually curved, about 40-50 » long, 4-5 p thick ; 
hymenial gelatine blue with iodine——Lecanora elatina Ach. 
Lich. Univ. p. 387 (1810); Cromb. in Journ. Bot. viii. p. 98 
(1870) & Monogr. i. p. 455; Leight. Lich. Fl. p. 231; ed. 3, 
p- 223. 
Differing from either of the preceding species in the much thinner 
thallus, and in the absence of reaction with potash in the fruit. The 
asci are thick-walled, the spores lie in a half spiral. Though 
extremely rare in the British Islands it has a wide distribution, more 
especially in Scandinavia. 
Hab. On the bark of old hollies.—B. M. Derrycuintry, Killarney, 
Kerry (the only British record). 
