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TRANSACTIONS OF THE 



face and 60 feet above the coaly consists of a dark blue 

 micaceous shalcj in which occur impressions and casts 

 of that fine fossi! plant Calamites SackoiDu. I obtained 

 specimens of the same fossii, apparently occurring under 

 similar circumstances, from two or three other shafts at 

 distant points in this coal field. M. iVdolphe Brong- 

 niartj who describes and figures this calamite, in his His- 

 toire des Vegetaux Fossils, plate 16, fig. 1, observes, 

 that although the external surface of the Richmond fossil 

 is indifi^erently preserved, he assigns it to this species as 

 a variety, on account of its general form and the thinness 

 of its bark. The sides are only more convex than some 

 other varieties described by the same writer, which may 

 be owing to a less compression ; for these stems, which were 

 probably vertical, appear to have been compressed in the 

 direction of their length, and exhibit numerous wrinkles 

 or folds, which seem to indicate how much their sides 

 were thin and flexible. This specimen is even very re- 

 markable under this point of view, and proves that the 

 stems were fistulous like those of the living equiseta."* 

 We may add, that this fokled or wrinkled character, of 

 which a good representation is given in the figure of M. 

 Brongniart, is common to every specimen we have seen 

 in this coal field. These specimens were from 8 to 12 

 inches in diameter near their base. From a dark mica- 

 ceous grit overlying the coal of the Chesterfield pits, we 

 obtained several specimens of impressions of smaller com- 

 pressed calamites, some of them not exceeding three- 

 fourths of an inch in diameter. 



Lignites, the vegetable matter of which occurs in a 

 carbonized form, abound in the grey and white grits 

 overlying the coal. I have not obtained them in a 

 sufficiently perfect form to enable me to determine the 

 class to which these fossil vegetables belong. 



* Histoire des Vegetaux Fossiles, p. 126. 



