DISCOVERY OF A WHITE FOSSIL POWDER. 263 
innumerable pieces of a square, rhomboidal, or oblong shape, 
united during life by vegetable matter, but in decay separa- 
ting at the joints into detached independent portions, the 
lines of separation being as clear and sharp as though cut by 
8 razor, and showing no trace of their previous union. Dr 
Greville’s botanical character of them is, that they are generally 
hyaline or transparent, rigid and fragile, in parallel series or 
circles, naked or imbedded in a mucous mass or gelatinous 
Jrond, and at length separating into definite segments. I may 
here observe, that though mostly parasitical and attached to 
larger species, many of them float loose in the water, in wiry 
entangled masses or detached little points, not larger than a 
pin-head, but when magnified, appear like radiated or starry 
globes, "These probably lie at the bottom of the water till 
the season of fructification, when they rise to the surface for a 
few weeks, and are so abundant that the fluid seems impreg- 
nated with curd or fecula, so as to attract vulgar observation. 
I have witnessed this singular appearance for several succes- 
Sive seasons about midsummer, in the broad deep lake near 
Ellesmere in Shropshire, where it is known as the * breaking 
2 of the water," as though the lake thus cleansed itself of its 
slimy extraneous matter. Some similar minute Conferva 
. 8ppears annually on the lake of Neufchatel, and attentive 
observation would probably detect it also in other similar 
_ Situations; and no doubt but the same causes which deposits 
. the powder under Lough Island Reavey, and Blyton Car, 
. restill in operation in favourable localities. The deposit is. 
still going on in Lough Island Reavey ; nor is it an impro- 
; le conjecture, that if ever by a slight elevation, the lakes 
of Ellesmere and Neufchatel come to be drained off, the 
. Temains of floating and parasitical Conferve may be found 
. Occupying a stratum along their former bottom, cover ed up 
by peat or bog moss. _ E 
—. Little more now remains for me than to state the result of 
My examination of the fossil powder now before us. Though 
80 impalpable as not to be felt between the fingers, and so — 
Minute that with an ordinary lens no organization canbe — 
