012 SUPPLEMENTARY NOTES. 
mals, is composed in part of Iron secreted by Infusorial animalcules 
of the Genus Gaillonella. This Iron may be separated from the 
siliceous shields of these animals, which retain their form after the 
extraction of the Iron. He has also detected similar ferruginous 
and siliceous remains of Infusoria in similar ochreous substances, 
from the Ural, and New York, and also in a yellow earthy sub- 
stance formed on the surface of the mineral water of the salt 
works at Colberg and Diirrenberg. This substance is used for 
iron colour in house painting at Colberg. The iron secreted by 
these animalcules, and connected with their siliceous shields, 
forms after death a nucleus to which other iron is attracted, from 
a solution of this metal in the water which these animals inhabit. 
In another communication. Prof. Ehrenberg announces that 
certain indurated and heavy portions of the Polierschiefer of Bilin, 
called Saugschiefer, are also the remains of Gaillonellse, cemented 
and filled with amorphous siliceous matter derived from these 
infusoria; and that nodules of Semiopal, which occur in the 
same Polierschiefer, are also composed of Silex derived from 
infusorial remains that have been dissolved and formed into sili- 
ceous concretions, having dispersed through them numbers of 
infusorial shields, partially dissolved, together with others that 
are unaltered. Ehrenberg also thinks he has found indications 
of microscopic organic bodies of a spherical form, (some, perhaps, 
allied to the existing genus Pyxidicula,) in semi-opal from Cham- 
pigny, and also in semi-opal from the Dolerite of Steinheim 
near Hanau, and from the Serpentine of Kosemitz in Silesia, 
and in precious opal from the Porphyry of Kaschau. In the 
white and opake bands of a few chalk flints, he has also found 
spherical and needle-shaped microscopic bodies, which he con- 
siders to be of organic origin ; these are most abundant in the 
white siliceous crust which forms the exterior of the flints, and 
in the mealy siliceous powder sometimes found within their 
cavities, but are not distinguishable in the black interior of the 
nodule. The existence of living marine species of Infusoria, 
renders it probable that animals of this class existed also in the 
early seas in which the stratified rocks were deposited. The fact 
that living Infusoria have the power of secreting Silex and 
Iron, places their fossil siliceous and ferruginous remains, nearly 
