510 136. Hypod. 6. SARCOTHALAMES. Pl, cell. aph. 
6. Hypoderma xylomoides. Xyloma hypoderme. 
Thece elliptical, flat, shining, black. 
Xyloma hysteroides, Persoon Syn. 106. 
Hypoderma xylomoides, De Cand. Syn. 823. 
On dead hawthorn and laurel-leaves. 
Til. 137. HYSTERIUM. Persoon. Hysterium. 
Thallus 0; thece long, naked ; mouth a simple linear slit. 
—On old dead wood. 
1. Hysterium mytilinum. Mussel hysterium. 
Thece aggregate, black-green, upright, lenticular, 
streaked crosswise, slightly pedicelled. 
Hysterium mytilinum, Persoon Syn. 97. 
On the bark of abies excelsa. 
2. Hysterium pulicare. Flea-brown hysterium. 
Thece gregarious, oblong, blunt, streaked, black; lips 
blant. 
Hysterium pulicare, Persoon Syn. 9S. 
Lichen scriptus 8, Lightf. Scot. 2, 801. 
On dead branches of oak-trees. 
3. Hysterium angustatum. Narrow-mouth hysterium. 
Thece crowded, linear, parallel, black; lips sharp. | 
Hysterium angustatum, Persoon Syn. 99. 
On decayed wood. 
B. SpHermex. Thallus fleshy, leatherlike, crustlike, 
or 0; ¢hece fixed, roundish, opening by a roundish mouth, 
sometimes remaining closed; sporidia long, mostly club- 
shape, twisted, deliquescing into a liquid slime; spore ob- 
long, ringed. 
IV. 138. XYLARIA. Hill. Xylaria. 
Thallus long, clubshape, fleshy; ¢hece roundish, in the 
circumference of the thallus; mouths circular. 
a. Growing on the earth. 
1. Xylaria militaris. Soldierlike xylaria, 
Thallus yellowish. red, head rough, rather tubercular ; 
mouth slightly prominent. 
