92 THE OLD RED SANDSTONE. 
such as might be formed by comminuted sea-weed. © (See 
Plate VIL) Some of the impressions fork into branches at 
acute angles, (see figs. 4, 5, and 6;) some affect a waved 
outline, (see figs. 7 and 8;) most of them, however, are 
straight and undivided. They lie in some places so thickly 
in layers as to give the stone in which they occur a slaty 
character. One of my specimens shows minute markings, 
somewhat resembling the bird-like eyes of the Stigmaria 
Ficoides of the Coal Measures;—the branches of another 
terminate in minute hooks, that remind one of the hooks of 
the young tendrils of the pea when they first begin to turn. 
(See fig. 3.) In yet another there are marks of the ligneous 
fibre ; when examined by the glass, it resembles a bundle of 
horse-hairs lying stretched in parallel lines; and in this speci- 
men alone have I found aught approaching to proof of a ter- 
restrial origin. The deposition seems to have taken place far 
from land; and this lignite, if in reality such, had probably 
drifted far ere it at length became weightier than the support- 
ing fluid, and sank.* It is by no means rare to find fragments 
* The organism here referred to has been since slit by the lapidary, 
and the sections carefully examined. Itproves tobe unequivocallya 
true wood of the coniferous class. The following is the decision re- 
garding it of Mr. William Nicol, of Edinburgh, confessedly one of our 
highest living authorities in that division of fossil botany which takes 
cognizance of the internal structure of lignites, and decides from their 
anatomy their race and family : — 
Edinburgh, 19th July, 1845. 
Dear Str:—JI have examined the structure of the fossil wood which you found 
in the Old Red Sandstone at Cromarty, and have no hesitation in stating, that the 
reticulated texture of the transverse sections, though somewhat compressed, clearly 
indicates a coniferous origin; but as there is not the slightest trace of a disk to be 
seen in the longitudinal sections parallel to the medullary rays, it is impossible to 
say whether it belongs tothe Pine or Araucarian division. Iam, &c., 
Wiuiram Nico. 
