C'ALTCIOI.] CALICIEI. 95 



This differs from the type in the upper portion or the entire length of 

 the stipes being concolorous with the underside of the capitulum. It 

 is probably an accidental state. Leighton erroneously describes it as 

 having a whitish margin. 



IIal>. On decaying wood in upland tracts. Distr. Very rare and local 

 in W. England. B. M. : Cricklade, Wiltshire. 



Var. /3. xylonellum Nyl. Syn. ii. (1860) p. 155. Capitulum 

 blackish, usually more globose, the margin inflexed, sometimes 

 brownish. Cromb. Grevillea, xv. p. 14. Calicium xylonellum Ach. 

 Meth. (1803) p. 92, Suppl. p. 14. Calicium sphcerocephalum 

 ft. crustosum Turn. & Borr. Lich. Br. p. 153. 



Though looking distinct, this is only a variety of C. trachelimnn, 

 differing, amongst other minor and less constant characters, in the colour, 

 form, and coarctate margin of the capitulum. 



Hab. On old pales in upland wooded tracts. Distr. Very local and 

 scarce in E. and S. England, and (fde Nyl. I.e.) in 8. W. Ireland. 

 B. M. : Bury St. Edmund's, Suffolk /Stone}' Cross, New Forest, Hants. 



1 3. C. parietinum Ach. Vet. Ak. Handl. 1816, p. 260, t. 8. f . 1 A, B. 

 Thallus very thin, maculate, greyish-white, or none visible. 

 Apothecia minute, scattered ; stipes somewhat short, slender, 

 black; capitulum lenticular or subturbinate, blackish, sporal mass 

 compact; spores fusiformi-ellipsoid, simple, about 0,007-11 mm. 

 long, 0,003-6 mm. thick. Cromb. Grevillea, xv. p. 14. Calicium 

 subtile Mudd, Man. p. 258 ; Cromb. Enum. p. 13 ; Leight. Lich. Fl. 

 p. 44, ed. 3, p. 44. Calicium debile Eng. Bot. t. 2462 ; Turn. & 

 Borr. Lich. Br. p. 151 ; Sm. Eng. Fl. v. p. 141. Strongylium 

 debile Gray, Nat. Arr. i. p. 484. As it is extremely doubtful if 

 Calicium subtile Pers. is this species, I have employed the name of 

 Acharius. Brit. Exs. : Leight. n. 314 ; Mudd, n. 247. 



The thallus, even when best developed, forms only a very thin, widely 

 spreading film, which often becomes obliterated. The minute, scattered 

 apothecia, the slender stipes, the form of the capitulum, the rather com- 

 pact mazsedium, and the simple spores distinguish it from its British 

 allies. 



Hab. On the trunks of decorticated dead trees, and on old timber of 

 outhouses in upland districts. Distr. Local and rare in S. and N. Eng- 

 land. B. M. : Henfield, Sussex ; Lyndhurst, New Forest, Hants ; Cleve- 

 land, Yorkshire. 



Form minutellum Nyl. Syn. i. (1860) p. 159. Thallus whitish. 

 Apothecia minute, capitulum often greyish-suffused beneath. 

 Cromb. Grevillea, xv. p. 14. Calicium minutellum Ach. Vet. Ak. 

 Handl. 1816, p. 118, t. 5. f. 2. 



This differs from the type in the colour of the thallus, the constantly 

 minute apothecia, and the colour of the underside of the capitulum. In 

 the only British specimen this last character is scarcely apparent. 



