482 119. Acolium. 4. CENOTHALAME SK. PI. cell. aph. 
XXIX. 119. ACOLIUM. Acharius. - Acolium. 
Thallus crustlike, flat, expanded, ¢dnate, uniform; apo- 
thecia cuplike, nearly sessile, cartilaginous, composed of a 
compact powdery mass forming a naked centre, the upper — 
part flat or nearly globular. 
1. Acolium tigillare. Rafter acolium. 
Crust in beds, wartlike, rather bald, lemon-yellow; apo- 
thecia sessile, deep black, opake, centre flat, border swollen. 
Lichen tigillaris, Achar. Prod. 67 ; Engl. Bot. 1530. 
Lecidea tigillaris, Achar. Meth, 46; Lich. 164, 
‘On old timber-work. 
2. Acolium tympanellum. Litile-drum acolium. 
Crust cartilaginous, smooth, afterwards rather warty, 
ameven, gray; apothecia sessile, black, centre flat, with a 
greyish hoar; border thin, even with the centre. 
Lichen inquinans, Engl. Bot. 810. 
Calicium tympanellum, Achar. Meth. 89; Lich, 233. 
On timber-work. 
When touched stains the fingers black. 
3. Acolium stigonellum. Dimpled acolium. 
Crust scarcely cracked, uneven, whitish, or 0; apothecia 
sessile, nearly globular, black, bald; centre dotlike, after- 
wards flattish, opake; border thin, naked. f 
Lichen gelasinatus, Withering Bot. Arr. 4. 
Lecidea gelasinata, Achar. Meth. 33. 
Spherocarpus sessilis, Ehrh. Crypt. 320. 
Spheria sphincterica, Sowerby Brit. Fungi, 386, 1. 
Calicium sessile, Persoon Tent. Fung. Suppl. 59. 
Calicium stigonellum, Achar, Meth. 88; Lich, 232. 
On the bark of oak-trees, and on the crust of porina per- 
tusa. : 
XXX. 120. PHACOTRUM. Acharius. Phacotrum. 
Thallus crustlike, flat, expanded, adnate, uniform; apo- 
thecia podicilled, centre powdery, flat or globular, border 
prominent.—The centre of the apothecia sometimes falling 
out, they are left hollow. . 
1. Phacolrum microcephalum. Small-headed phacotrum. 
~ Crust rather tartarlike, not broken, wrinkled, olive- 
colour ; apothecia nearly globular, black, shining; centre 
depressed, opake; podicils short, similar in colour. 
Lichen microcephalus, Engl, Bot. 1865. 
Calicium microcephalum, Achar. Syn. Lich, 57, 8. 
On oak-wood. 
