Dr. Mantell on Fossil Foraminifera. 71 
usual appearance of the fossil Rotaliz 
filled with chalk when viewed by trans- 
mitted light, and rendered semi-transpa- 
rent by Canada balsam, is shown in the 
accompanying figure, (1.) 
The unequivocal organic structure, 
however, discernible in the substance 
contained in the cells of the Rotalie by 
a high magnifying power, and of which 
ho traces are observable in the mineral 
casts, and the identity of appearance in the fossils and the cor- 
rugated animal body in the Levant specimens, convinced me of 
ral examples of the soft bodies of Rotalie in an extraordinary 
State of preservation, from the grey chalk of Folkstone. 
‘To Mr. Henry Deaue of Clapham Common, an able chemist 
and microscopical observer, I am indebted for the most illustra- 
live specimens ; accurate figures of which, drawn by Mr. Moun- 
Sey, and M. Dinkel, are subjoined. ‘These relics were obtained 
by subjecting a few grains of the cretaceous rock to the action 
Weak hydrechloric acid, by which means the calcareous earth, 
and the shells it enveloped, were removed ; the residue consisted 
of particles of quartz, and of green silicate of iron, with which 
the chlorite chalk abounds, and numerous remains of the soft 
parts of anifmaleules. A small portion was then prepared in the 
usual manner with Canada balsam, and this was found to contain 
many Xanthidia, and the Rotalie hereafter described. 
‘Thave not had an opportunity of examining the structure of 
the living Rotalie ; but from the recent observations of Ehren- 
erg, It appears that the organization of these minute animals 1s 
very simple, and has no relation whatever to that of the Cepha- 
Pes 3 WwW ich ; 
Rotalia, therefore, though presenting the general form and cham- 
parts ; butin the instances under examination, 1 conceive that the live animal was 
suddenly enclosed in its shell, and hermetically sealed, as it were, by the investing 
d thus the usual putrefactive process 
