186 ORGANIC REMAINS. 



sandstone as that which is without. Hence we may regard them as 

 casts, rather than petrifactions. 



This last i-emark applies to another class of vegetable re- 

 mains, found in the sandstone, and sandy bituminous shale, — those 

 cylindrical fossils, which have their surfaces adorned with curious 

 markings, disposed in rows in the quincunx form. These markings 

 correspond with the impressions made by the leaves of trees of the 

 pine family ; the roots of the leaves, especially in the young bi'anches 

 of such trees, making rows of indentations, placed in the same style, 

 around each branch. Specimens of this kind have been found in the 

 sandstone, several feet in length, and displaying in the cfoss section 

 a mark in the centre, corresponding with the pith of the tree. The 

 indented impressions are always alike in the same specimen, but vary 

 in different specimens. Two fragments are given as examples, Plate 

 HI, Fig. 4 and 5 : the former of which is from the sandy shale, or coaly 

 sandstone, connected with the coal ; the latter, with the arrow-head 

 markings, from the hard sandstone, or crow-stone. Several other 

 varieties occur. In some, the indentations consist of minute circles, 

 each having an elevated point in its centre; in others, the surface is 

 beautifully reticulated and dotted, having elegantly waved lines, like 

 those of No. 4, running between the rows of indented marks. 



Nodules resembling nuts or fruits are not uncommon in our 

 strata, especially among the aluminous beds; but real petri- 

 factions of fruits are rarely met with. Figure 7 of Plate III is a 

 petrified nut of a singular kind. It is from the ironstone nodules 

 occurring in the sandstone, in the cliffs on the west side of the 

 battery at Whitby ; where it was found by Dr. Campbell. The 

 crust, or shell, is of hard ironstone, of a dark reddish brown hue, and 

 marked with high longitudinal ridges, finely striated. The nucleus, 

 or kernel, which is laid open at the top, where the shell has been 

 broken, consists of a soft pale grey earth, or ochrey clay. 



