about it, as I do not now think it belongs to Boletus hybridus, "promoting putrefaction, dissolving and destroying the hardest wood." Linn, but as probably Byssus septica, which is promoted by putrefaction, and caused by rotten hoops on pipes of wine, &c. and is never white or like Dillenius, tab. 1, fig. 9. Withering's variety 2 is distinct, and the proper species growing on wine casks, and the hoops, &c. in wine cellars, as well as in ale and beer cellars.
It is apparently composed of minute fibres, closely matted together, and partly covered with fine dust, and grows in masses of the size of a pea, an acorn, a walnut, or spreading, and is in cellars or vaults, attached to the sides and cielings, hanging in large accumulated masses of several feet wide; scopiform, clawed, fingered, and in inosculating or fanciful shapes. It is very tender, burns Avhen dry like touchwood. It is of a greenish brown when small, and blacker when older and more massive. The smaller lumps, if thrown when fresh against any thing, stick to it.
TAB. CCCCXXXIII.
FIBRILLARIA pulverulenta.
This was found three feet under ground, on rotten wood, near Reading in Berks, in April, 1809; it appears more compact than the last, more powdery, and of a rather redder brown; otherwise the fibres, when magnified, scarcely differ from it.
TAB. CCCCXXXIV.
FIBRILLARIA corticina.
This I have found on the inner and outer sides of the bark of trees, covering it in wide, black, fibrous, cloth-like patches, the sixth of an inch thick. Sphæria bombardica, tab. 372, fig. 4, often accompanies it on the outside of the bark. Kensington Gardens, Hornsey Wood, &c. in autumn.
TAB. CCCCXXXV.
TRICHIA metorica.
TREMELLA metorica. Linn. Gmel. 2. 1446. Persoon.
The utility of figuring this under this title will be obvious, seeing the nature of the substance, and how it has misled, and still may mislead, and that it may be the means of coming to a more perfect knowledge of it. There are various Genera among the Cryptogamia which have a mucilaginous and tremulous beginning, very different from their more advanced and latter state, and these when gathered in their young state dry and become of a horny texture as gelatinous substances do, but when suffered to arrive at maturity, not only
