Notice of Ehrenberg's Memoir on Microscopic Life. 313 



the whole extent and influence of microscopic life in America can 

 be fully understood and appreciated. Hundreds of species of ma- 

 rine and fluviatile siliceous infusoria, not mentioned in Ehren- 

 berg's list, are known to us, and myriads of the more perishable 

 forms occur in all our waters. The soft and gelatinous forms of 

 these must prevent their being sent across the Atlantic, and it 

 remains for our naturalists to compare them with the European 

 species represented in Ehrenberg's magnificent volume on infu- 

 soria. Important information with regard to the infusoria of the 

 United States has already been accumulated by several of our 

 naturalists, among whom we may mention the names of Thomas 

 Cole, Esq. of Salem, and Dr. P. B. Goddard, of Philadelphia, both 

 of whom are accurate and zealous observers. 



With regard to our Polythalamian forms, we can state, that they 

 exist at various localities not yet known to Ehrenberg. Besides 

 the numerous living species of our coast, our tertiary formations 

 are filled with characteristic and beautiful forms which we have 

 detected in specimens from various localities, as Petersburg, Va., 

 Wilmington, N. C. We have also found them in marl from near 

 Astoria, Oregon Territory, brought by Mr. James D. Dana, and in 

 carboniferous limestone from Indiana, furnished us by Dr. David 

 Dale Owen. We have gradually accumulated many figures of 

 these forms which we intended for publication, but as Ehrenberg 

 has now undertaken the subject of American Polythalamia, we 

 believe that we cannot do better than to place all our materials in 

 his hands; and as it is desirable to supply him with specimens 

 from as many localities as possible, we take this occasion to invite 

 the friends of science, who may be so situated as to be able to com- 

 ply with the request, to forward to us specimens of the cretaceous 

 and tertiary deposits of the United States. Specimens from the 

 " rotten limestone" of Florida and Alabama, and from the cretace- 

 ous beds of Tennessee, &,c. are highly desirable. Even the mi- 

 nute portion which can be sent in a letter will often give most 

 important and valuable results. Specimens of the sediment of 

 our rivers and harbors, particularly from those of the southern re- 

 gions of the United States, will also be very acceptable.* 



* Specimens may be sent addressed to J. VV. Bailey, West Point, N. Y., care of 

 Dr. J. R. Chilton, 263 Broadway, New York; or to B. Silliman, Jr., New Ha- 

 ven, Conn. 



Vol. xlvi, No. 2.— Jan.-March, 1844. 40 



