DR. MANTELL ON FOSSIL FORAMINIFERA. 
469 
ages that must have elapsed since the deposition of the chalk in which it was en- 
shrined, is a fact not less remarkable than the occurrence of the carcase of the Lena 
Mammoth, in the frozen soil of Siberia. 
In another example (fig. 7), a series of sacs, held together by the connecting tube, 
is uncoiled as it were, and extended in a longitudinal direction ; proving the flexible 
nature of the original substance. 
On examining by reflected light, under the microscope, some pieces of chalk col- 
lected from the stratum which yielded the fossils above-described, minute particles of 
a brown colour may be observed scattered over the surface ; these I have no doubt 
are remains of the integuments of foraminifera ; for in one instance, three cells of the 
shell of a Rotalia lined with a similar substance, were exposed. Mutilated Rotalise, 
consisting of only four or five sacs (figs. 2, 3), and sometimes of but one (fig. 4), are 
common both in chalk and flint; and these invariably have a torn and collapsed 
appearance. 
The fossil organisms termed by Ehrenberg Xanthidia, which have long been known 
in flint, and were formerly considered to be siliceous, have been shown by Mr. 
Deane to occur in the chalk in a similar condition to the Rotaliee ; an unequivocal 
proof of the flexible nature of the original (see fig. 1). 
That the correctness of the statements embodied in the preceding remarks maybe 
verified, I submit the specimens to the Royal Society for examination under the 
microscope. 
I will only add, that if the explanation I have suggested of the facts described be 
correct, and the fossils before us are the delicate soft parts of animalcules preserved 
in chalk and flint, in like manner as the bodies of mollusks occur as a carbonaceous 
substance in the Wealden freshwater limestones — this discovery, though relating to 
some of the minutest forms of existence, may yet prove an important element in 
many of the most interesting speculations of the geologist ; for in strata in which 
no vestiges of shells, corals, or other dense organisms have been detected, the relics 
of countless myriads of beings may lie concealed*. 
* In confirmation of these views I may state, that Dr. Bailey, Professor of Chemistry in the United States 
Military Academy at West Point, whose high attainments as an accurate microscopical observer are well- 
known, had arrived at the same conclusions, from the examination of American specimens, before he was ap- 
prised of the result of my researches. In a recent communication, he informs me that he has obtained, from 
the marls of New Jersey, not only casts of the interior of the shells of Rotalice and Textilaricc, but also the soft 
bodies of the animals, in the condition of molluskite. I have detected similar specimens in marl from the same 
locality, sent to me by Dr. Bailey. 
Chester Square, Pimlico, 
May 1846. 
