308 Notice of Ehrenberg’s Memoir on Microscopic Life. 
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The specimens from Missouri, Mississippi, and New Jersey, sent to me 
by Prof. Bailey in 1842, for further examination and determination of 
the forms, have removed all doubts concerning this exceedingly great 
influence of minute life, which must now be looked upon as a well 
established scientific fact, and must be attended to in considering the 
geognostic relations of the earth, and partigplarly the development of 
the surface of the earth in all central North America. It would lead 
too far, to give all the particulars of the rich results lately obtained from 
these examinations, and as I shall have occasion, ina larger work which 
is now nearly completed, to present all these details with drawings 
comparing all the chalk formations of America, Europe, Asia and Af 
rica, I limit myself to this general notice. But be it remarked, that 
many of the species of European chalk Polythalamia also occur in 
Asia, Africa, and America,* while some are wholly local. To the lat- , 
ter belong the Textilaria Americana,+ whose first and lowest cells are 
round, while the upper largest cells are always wart-like, longer, | 
sharper, and at last terminate in a point. This species forms the prin 
cipal mass of the chalk of the Upper Missouri. Whether flint, or ils 
equivalent, chalk marl with marine infusoria, occurs there, is still un 
known, and is very desirable to determine.” 
Part IV, contains an alphabetical list of all the microscopie 
American infusoria mentioned in this work, with the localities at 
which each has been found. ; 
Part V, gives the characteristics of the new genera and species 
Part VI, includes the general results of the examination, viz. 
1, There is here presented the first general view of the hitherto ut 
known character of the surface of the earth, for all zones of the wh 
continent of America. 
2. It proves that not only in situations rich in humus, but also in 
sandy places of the surface of America, from near the south to neat 
the north pole, there exists an organic life generally invisible to the ey 
and that the bottom of the sea is filled with such organic forms. 
a 
* The identity of some of the American Polythalamia with those of England, 
Africa, and Asia, was made known by us in this Jour- 
nal, Vol. x11, p. 400, and in the Proceedings of the 
American Association of Geologists and Naturalists, Vol. 
I, pp. 356-7 
t Ehrenberg gives no figure of this species, but it un- 
doubtedly is the same as that represented in outline in 
the annexed cut, which we have drawn from the spe- 
cies most abundant in our specimens of the Missouri 
chalk marl. Outlines of some of the other forms will 
be found in this Journal, Vol. xx1, p. 400. 
