CRYPTOGAMIA Algae.
G en. Char. Male, scattered warts.
Female, smooth shields or tubercles, in which the
seeds are imbedded.
Spec. Char. Crust irregular, thin, uneven, smooth,
cracked, greenish white. Shields clustered, minute,
hollowish, irregular, greyish black, with an elevated
irregular margin of the substance of the crust.
Syn. Lichen agelasus. Ach. Prod. SO.
Urceolaria agelsea. Ach. Meth. 150.
T h i s obscure Lichen is found by Mr. Turner about Yarmouth,
and Mr. W . Borrer in Sussex, and is said by those
gentlemen to be not uncommon on the barks of trees, though
described only by Dr. Acharius from the communication of
his learned friend Swartz. We have often observed it in its
whitest early state, and have neglected it as a form of L.Jh-
gineus, t. 1713, or discoideus, t. 1714, from both which
however the slightest examination proves it to be distinct;
The young crust spreads in irregular oblong transverse
patches round the stems of large trees, and is thin, smooth,
somewhat shining, of a pale greenish white, sprinkled with
roundish, white, warty cracks. These' at length become more
elevated, and are separated from one another by angular
fissures, which render the crust tessellated. At length, several
small blackish depressed shields, extremely irregular in size
and shape, appear in each of those warts, every one of which
shields is surmounted by a thick shapeless elevated indexed
margin, of the substance of the crust.