PLcelLaph. 5. IDlOTHALAMEiE. 134. Hysterina. 507 
Graphis microscopica, Ehrh. Crypt. 278. 
Opegrapha microscopica, Eng l. Bot. 1911. 
Opegrapha epipasta caruganae, Achar. Meth. 26; Lich. 258. 
On the smooth bark of trees, mostly in company with 
lejophlea analepta, gen. 128, 2. 
1 1 . Hysterina venosa. Veiny slit-moss . 
Crust powdery, white; apothecia close together, branch- 
ed, stuffed, prominent, bald. 
Opegrapha venosa, Persoon in Act. Wetter. 2, 44 ; Achar. Syn. 334. 
On the trunks of beech-trees ; always surrounded with 
arthonia obscura, gen. 117j 3. 
12. Hysterina denigrata . Smutted slit-moss . 
Crust regular, membranaceous, palish-white; apothecia 
sessile, crowded, rather shining, longish, bent, sometimes 
branched; centre slightly channelled. 
Opegrapha atra, Persoon in Uster Ann. 7, 30. 
Opegrapha denigrata, Achar. Meth. 26; Lich. 259; Engl. Bot. 1753. 
Opegraplia denigrata melanochroa, Achar. Meth. 27. 
Opegrapha denigrata atra, Achar. Lich. 260. 
On the bark of wallnut, ash, oak, and beech trees. 
Earn. VI. 6. SARCOTHALAMEiE. Fungorum pars , 
Linnseus. Hypoxylorum pars , De Candolle. 
Xylaria , Link. Myelomyci , Esenbeck. 
Algarum pars , Jussieu. 
Thallus corky, fleshy, or 0 ; thecce mostly immersed in 
the thallus or substance of the plant, coriaceous or bony, 
of a different substance from the thallus, opening by a re- 
gular mouth, sometimes but rarely bursting irregularly; 
sporidia ringed, intermixed with a deliquescent, deciduous 
pulp. — Grows generally on decayed plants, under the epi- 
dermis. 
A. Sporidia fixed; thecce opening ly a slit ; thallus 0. 
Hysteridese. 
Theca roundish, erumpent; 
mouth valvular ; Actidium. 135. 
Theca long, erumpent ; mouth linear Hypoderma. 136. 
Theca long, naked; mouth linear .... Hysterium. 137. 
