36 



what crenulate margin ; a colored, rarely black, connivent proper 

 exciple, which is now explanate. veiled by an often evanescent thai- 

 line one. Paraphyses laxly coherent. Spores 2-4-plurilocular, or 

 muriform, uncolored. Thallus uniform. A small difficult genus. 

 9 spp. 



Genus 38. Theloteema. Apoth. urceolate, or now verrucae- 

 form, or endocarpeine, but at length largely scutellate ; the disk 

 veiled by an inner exciple (often obsolete) , the proper exciple vari- 

 ously colored, somewhat torn-margined, concrete with the thallus. 

 Spores 2-plurilocular, or muriform, brown or decolorate. Thallus 

 uniform. A large and difficult, mostly tropical genus. 12 spp. and 

 1 subspp. Two spp. occur in N. E. 



Genus 39. Gtrostomum. Apoth. from urceolate finally explan- 

 ate, orbicular, or often elongated-difforra ; a black proper exciple 

 with entire margin, clothed at first by an evanescent thalline one. 

 Spores muriform, brown. Th. uniform. A genus of one tropical sp. 



[Mybiangium has Lecanoroid apoth., which are multilocular, each 

 locule containing a single theke, with muriform colorless spores, and 

 innate in a rounded, plaited or lobed thallus, which is without go- 

 nidia. Hence its claim to be considered a Lichen is doubtful. The 

 single sp. occurs on the Atlantic coast.] 



Tribe II. LECIDEACEI. Apoth. rounded, marginal (normal- 

 ly) only by the proper exciple (patellaeform.) 



Fam. 1. Cladokiei. Thallus twofold, (1) vertical, (a Podeti- 

 um) ascending from, (2) a horizontal squamulose or crustaceous 

 one ; the latter now obsolete. 



Genus 40. Stereocaulon. Apoth. patellseform, brown, at 

 length convex, and the margin excluded, (cephaloid), solid. Spores 

 fusiform or acicular, 4-plurilocular, colorless. Th. fruticulose, 

 erect, solid, more or less clothed with granules, passing now into 

 fibrils ; horizontal thallus granulose or obsolete. A large genus, 

 throughout. 10 spp. 



Genus 41. Pilophorus. Apoth. cephaloid, solid, black. Spores 

 simple, colorless. Podetia simple or little branched, originally solid, 

 clothed with wart-like granules (phyllocladia) , which are also col- 

 lected into a crust at the base. A small genus of Alpine and Arctic 

 regions. 1 collective sp. 



Genus 42. Cladonia. Apoth. mostly cephaloid, empty within, 

 variously colored but not black. Spores simple, colorless. Pode- 



