F 
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FOSSIL BODIES OF ROTALIZ. 357 
the Rotalia, and allied forms, the body of the animal ig 
inclosed within the shells, and occupies every chamber con- 
temporaneously at every stage : the cells are always filled by 
the segments of the body. Hence when the shell, which is 
calcareous, is dissolved in weak hydrochloric acid, the soft 
body is exposed, ard seen to extend to the innermost 
chamber. The segments are connected by a membranous 
tube, which some naturalists regard as a common channel of 
communication between the several digestive sacs of which 
the body consists ; for minute diatomaceze which the animal 
has swallowed, (according to Ehrenberg,) are seen within 
the membranous sacs ; as shown in Lign. 113, which repre- 
sents the body of a Nonionina, deprived of its shell. The 
importance of obtaining a correct idea of this structure will 
presently appear. 
When a recent Rotalia is immersed in dilute acid, the 
soft parts of the body, deprived of the shell, may be obtained 
entire ; they consist of a series of little bags or sacs, united 
by atube. The constituent substance appears to be a tough 
membrane, and is generally of a rich brown or amber 
colour. The sacs are sometimes full of a granular substance, 
but are often empty and collapsed. 
FossIL REMAINS OF THE SOFT PARTS OF FORAMINIFERA. 
Lign. 113.—When examining chalk* and flint under the 
microscope with the view of discovering the fossil bodies 
described by M. Ehrenberg, I observed that the cells of the 
Rotalize in flint were frequently occupied by a substance 
varying in colour from a light amber to a dark brown, and 
closely resembling in appearance the body of the recent 
foraminifer deprived of its shell. Under a high power, the 
folds of the membranous sacs and the connecting tube were 
apparent, and I felt convinced that the substance filling the 
cells was not inorganic, but the original animal tissues in 
* In 1845. 
