[ 1830 ] ' f t
CRYPTOGAM1A Algae. .
Gen. Char. Male, scattered warts.
Female, smooth shields or tubercles, in which the
seeds are imbedded.
Spec. Char. Crust determinate, tessellated, olive-grey
with blackish cracks. Shields black, at length
convex, with a black border of their own substance.
Syn. Lecidea cechumena. Ach. Meth. 48.
Lichen scytropus. Ach. Prod. 79 ?
Verrucaria fusco-atra. Hoffm. PI. Lich. v. 3 .1 1 . t. 54.
/ 1* _ _ _ _ _
T h i s belongs to a very obscure tribe of Lichens, the synonyms
of which are remarkably confused; but we shall endeavour
to ascertain the species, step by step, as they fall in
our way, by a comparison with authentic specimens, aided by
the practical remarks of our correspondents. Tab. 1/37, and
t. 1829, are of this tribe.
The plant before us grows on granite or whin-stone rocks,
and was sent by the Rev. Mr. Harriman from Durham. Its
crust is uninterrupted, hard, uneven, of an olive or brownish
grey, somewhat glossy, broken into innumerable small angular
fragments, each of which is usually concave, and remarkable
for being black-edged, especially in that pretty variety
called by Acharius diffracta. The shields are numerous,
a little prominent and convex, black, with a narrowish black
border of their own colour and substance, but no spurious or
accessory one from the crust.
D cc.i.iSoJ.Pubtish'd by Ja ? SowerbyJjondan.