A. M. EDWARDS ON FOSSIL DIATOMACE^I. .3 



in the Carboniferous period, but I have not examined them as 

 they do not occur here. They were probably deposited in 

 comparatively quiet water of no great depth, and it was fresh 

 water, as there are no marine fossils. The Newark sandstone 

 was formed in damp meadows, not marshes, containing pools of 

 water of no great extent or depth ; for the DiatomaceaB in it are 

 not the same as now occur in wet, but merely moist meadows, 

 such as those around Newark, and the same diatoms exist 

 there now in the same circumstances. I think, too, the 

 temperature was the same in the Newark period as in the 

 meadows between Newark and Jersey City at the present time. 

 Ferns grew in the meadows, but no trees, and animal life was 

 scarce. This accounts for the occurrence of shaley sandstone 

 on the top of the red and white sandstone. 



Now I have carried the Diatomacese down to the Newark 

 period, which is much lower than the Lower Miocene, the 

 Tertiary, to which Virginia, Maryland, New Jersey, and Cali- 

 fornia belong, if indeed they be as old. And I wish to show 

 they are in the Lower Silurian also, the oldest rocks except the 

 pre-Cambrian and Laurentian, in which M. Cayeux found 

 Eacliolaria and Sir W. Dawson Foraminifera, viz., the Eozoon. 

 In the Hudson River epoch of the Lower Silurian age I have 

 found Diatomaceae, and they are of the same forms as occur at 

 the present time. I believe, of course, in evolution, but why 

 certain Mollusca, Foraminifera, and Diatomaceae have remained 

 unchanged up to now I, of course, cannot tell. 



They have been using for ballast and filling at Lyon's Farm, 

 N.J., on the Lehigh Valley railroad, material brought from 

 Jutland, N.J. It consists of shale mixed with slate. The 

 shale is yellowish or reddish, and breaks down readily w r hen 

 exposed to the air; the slate is blue-black in colour. The 

 shale sometimes passes into a yellowish clay, and in it occa- 

 sionally are spots of white clay. I have examined the latter, 

 and was delighted to find some Diatoruacese in it. They are 

 fresh-water forms corresponding with those growing in fresh 

 water now, and the species enumerated below are identical 

 with those now found in existing meadows which show no sign 

 at all of evolution. It is well to remember then that as evolu- 

 tion has not affected the Diatomaceas in all the millions of 

 years since the Hudson River epoch shale was thrown down, we 



