10 
CRYPTOGAMIA. ALG. Lichen. B. (2) Crustaceous, 
with TUBERCLES. 
Hoff. enum. 3.6, but the tubercles represented as if white. 
Crust granulated, hard, dry, very widely spreading. Tuber- 
cles convex, of the size of mustard seed. Huns. In its young 
state the crust is thin and smooth. When more advanced the 
crust cracks, and the fructifications begin to appear, but at first 
not raised above the crust, and not easily to be distinguished 
from it. . When older still the crust is very much cracked, the 
portions raised up, convex, granulated ; the tubercles very nume- 
rous, raised above the crust, convex, smooth. “The. specimens 
which gave rise to these remarks, were communicated by Mr. 
Griffith, also another specimen which had grown in.the shade, 
wherein the crust is thin and even, not black but: blackish 
brown ; the tubercles black with a smooth polished surface. 
Mr. Griffith has discovered a further change in this Lichen, 
as curious as it must be unexpected, and which is sufficient to 
shew that many discoveries yet await our enquiries in this sin- 
gular tribe of piants. I shall transcribe his own words.—** In 
the more advanced state of L. niger, small glaucous leaves issue 
from the dark » which in time form the imbricated L.. 
lumbeus. The dark ground (which is now of a spongy texture,) 
Sica elevated, and forms that cork-like substance which is at- 
tached to the L. plumbeus.”? 
Rocks and large stones about St. Ives, Cornwall, posits, | 
— about Kirkby Lonsdale, Westmoreland, Dr, J. E. 
mitH. About Garn, abundantly. Mr. Grirrita ; on Lime- 
stone. } a P, Jan.—Dec. 
fusco-a'ter. Lb. Tuberclés black, not bordered ; crust brown. 
Ckde‘ri, 
Hoffm. lich. 54..1-1. Facq. coll. g: Fs 14; 3, as on rocks ; 
4 as on trees. ig eco e, 
Crust rough, mealy, thin, hardish, closely adhering, dirty 
obscure grey. -Tubereles lentil shaped, convex, black, not bor- 
dered with a different colour. Jaco. Tubercles rough, black 
throughout. 
On rocks and stones. _[On_ trees. at Enville, Staffordshire. 
On the stone coping of a wall at Edgebaston. } a 
_  #P Jan.—Dec. Reruan. July. 
Var. 2. Tubercles black : crust none. Scop. p. 364. We- 
ber p. 191. Hagen. p. 49. 
_ On soking it in water some very fine branny fakes sepa- 
rated from the indurated clay on which it grew. 
_ [Onamud wall. Specimen from Major Velley.—On-rocks 
inthe north. Dr. Arexanper.] 
L, Tubercles black, with an indistinct black border; partly 
imbedded in the crust: crust rusty red, rough, _ 
cracked. 
