26 CYCLOCARPINE® 
zone (heteromerous). The thallus containing bright-green alge is 
non-gelatinous, and nearly always heteromerous. 
The Natural Orders are grouped as follows :— 
Thallus homoiomerous, gelatinous when y 
moist (more or less). Algze blue-green, 
distributed equally through the thallus. 
Thallus with Scytonema or Stigonema 
alge, more or less minutely fruticose... iii. EPHEBACE2. 
Thallus with Glwocapsa alge, crusta- 
ceous, minutely squamulose or minutely 
EPTUICOSE 2 > .n2: 22 do0 Woy veers oc doves eee ee iv. PYRENOPSIDACER. 
Thallus with Rivularia alge, fruticose 
or squamiulose, ‘Amiall..:..205,.ce. sacs areas v. LIcHINACEX. 
Thallus with Nostoc alge, crustaceous, 
squamulose or foliose..............ses.e+ses vi. COLLEMACER. 
Thallus heteromerous, not gelatinous when 
moist. Algs in a definite zone. 
Alge blue-green (bright-greenin Psoroma). 
Apothecia small. 
Thallus crustaceous, squamulose or 
Subiolioseymunue esse eee vii. PANNARIACER. 
Algz blue-green or bright-green. Apo- 
thecia large. 
Thallus foliose. Spores septate. 
Apothecia without a thalline 
margine, adnate ............s-.02 viii. PELTIGERACER. 
Apothecia marginate, scutellate ix. STICcTACER. 
Alge constantly bright-green (or yel- 
lowish). 
Apothecia large, with thalline margin. 
Thallus foliose. Spores simple x. PARMELIACER. 
Thallus frnticose. Spores simple 
OF SCPtate. ni icc ..nceonerereceenn xi. USNEACER. 
Apothecia small to moderate in size, 
with thalline margin. _ @ 
Thallus various. Spores polari- ; 
bilocwlan 4 sts. .-csinds nak feces xii. PHyscrackE®. | 
Apothecia usually small, with thal- 
line margin. ' 
Thallus crustaceous or minutely . 
squamulose. 
Apothecia single, superficial 
(or immersed at first). 
Spores various.............. xiii. LECANORACEX. 
Apothecia several in thalline 
VORTUOD 54. sincucenenpen Celts xiv. PERTUSARIACER. | 
Apothecia with a double 
WNATPIN: ..1003vcnsien see eeees xv. THELOTREMACES. 
Apothecia without a thalline margin. 
Thallus foliose, expanded......... xvi. GYROPHORACER. 
Thallus squamulose, with up- 
right podetia ...........ccseeceees xvii. CLADONIACEA. 
Thallus filamentous................ xviii. C@NOGONIACER. 
Thallus crustaceous or minutely 
BQUMAMULOBO ss cies ce ves andaquneedes xix. LECIDEACER. 
