394 Miscellanies, 
infusoria, sent for his examination by Professors Silliman, Bailey and 
Hitchcock. The chief results of his examinations of American species 
are— 
1. In North and South America, there occur not only living but fos- 
sil microscopic organisms, forming strata geologically important, and ye- 
ry similar in their relations to the European 
2. The American forms are for the seat part similar to the Euro- 
pean 
3. ‘One hundred and forty-three species are common to Europe, and 
seventy-one, or one third, peculiar to America. 
4. Not one of the American infusorial deposits resembles in its ele- 
mentary forms the chalk marl of the south of Europe. Nevertheless 
there is found in the deposit near Spencer, Mass. the Rotalia globulosa, 
which is decidedly peculiar to the writing chalk. 
(This statement of Ehrenberg was made before he was aware of the 
discovery made by Prof. W. B. Rogers of the tertiary infusorial strata 
in Virginia. I have shown these strata to agree with those of Oran, &c. 
in containing immense numbers of the same species of Actinocyclus, 
Coscinodiscus, Dictyocha, &c. which characterize the chalk marls of 
Oran, Caltasinetta, &c. Some of these species I have seen still living 
in our waters, not only on the sea-shore, as at Boston harbor, but also 
sixty miles up the Hudson river. 
The occurrence of the marine Rotalia globulosa in the infusorial de- 
posit of Spencer, an inland town of Massachusetts, would lead to curi- 
ous inferences were the fact well established; but having repeatedly 
examined specimens from that locality, and never having seen in them 
any but fluviatile organisms, I am inclined to think that a portion of 
chalk may have been accidentally mixed with Ehrenberg’s speck 
mens.—J, W. B. 
5. Most of the fossil deposits in North America are found in peat bogs, 
and contain forms of infusoria clearly referable to the brackish fresh-wa- 
ter forms of the sea coast, although some of them are at a great distance 
from the sea. 
(I found some of the most common fossil species, still living; as far 
west as Quisconsin river.—J. W. B. 
_ 6. Catalogue of American infusoria determined by Ehrenberg: 
Eunotia Monodon 
