COAL ROCKS OF EASTERN VIRGINIA. 303 



layers in the slaty rocks, or is impressed on the parting surfaces 

 of some varieties of the coal. Nor is the resemblance less perfect 

 between the uncompressed form of the Brora fossil as represented 

 in figures 1 and 2 of the Memoir, and the cylindrical jointed 

 stems marked near the joints with similar grooves and ribs, 

 already alluded to as occurring in certain soft sandstones and 

 argillaceous beds in the Virginia localities. I have therefore no 

 hesitation in considering the Virginia fossil as identical with that 

 of Brora, as well as with that referred to by Prof. Phillips in his 

 Geology of Yorkshire, as occurring in the sandstone at High 

 Whitby, and recognized by him to be the Brora fossil. Guided 

 by the authority of Brongniart, who describes specimens from 

 Brora, Whitby, and other European localities, I shall hereafter 

 speak of our fossil as the Equisetvm. columnare. 



In all the British localities of this fossil, as Whitby, Haiburne, 

 Wyke, and Brora, it occurs in connection with carbonaceous 

 beds, appertaining to the Loiver Oolite. In the neighborhood of 

 Balbronn, Gemonvel, Studtgard, and other localities on the Con- 

 tinent, it is found in geological connections less certainly deter- 

 mined, but which Brongniart infers to be the same as those in 

 which it occurs in Great Britain. In closing his account of this 

 fossil, Brongniart says : " In England, where the secondary forma- 

 tions have been so well studied, no trace of this plant has yet 

 been found in the lias, or in the more ancient beds, or in the Ox- 

 ford clay and more recent formations ; nor does any thing in the 

 Stonesfield limestone or Tilgate limestone, indicate the presence 

 of this plant, which ive may therefore consider as characterizing 

 the loiver beds of the Jura limestone " {the Loiver Oolite). 



Equisetum arundiniforme. 



The fossil for which the above title is provisionally proposed, 

 bears a close resemblance to the stem of a common reed, bruised 

 and flattened by pressure. The most perfect specimen in my 

 possession is on a light gray, slightly micaceous slate. The stem, 

 which is flattened out, is fifteen inches long, and two and a half 

 to three inches wide, divided by joints about four inches asunder. 



