Other very perfect casts of Sigillariæ, as well as of Lepidodendra, have also been found in the black shale. In the same shale, and about the same locality, an imprint of a species of large reptile was found, probably of the order Crocodilia. The imprint was very perfect, and many feet in length, but unfortunately the native workmen then engaged in throwing down this “reef” had thrown down to the bottom of the mine every vestige of the fossil, before a friend of the writer requested Mr. William McHardy (then and now manager of the Central company) to procure a specimen for him. Mr. McHardy saw this cast himself and informed my friend of the find, and at his request (my friend’s) he at once returned to save it, but unfortunately not a vestige of it was to be found, the natives having thrown a vast quantity of reef down, so that the proverbial needle in the bottle of hay was easily discernible in comparison with my friend’s fossil cayman. Other interesting fossils have been found in these shales, and have been deposited by their owners in various museums in Europe and America.
This concludes an account of all the fossils in the shales of which I can give any authenticated delineation, but I may mention that dendrites are very common in the light shales, caused by iron stains, mostly of a dark red color. I have already stated in the body of the chapter relating to the Kimberley mine that coal, from a mere trace in thickness to eight or ten inches, has been found in the black shales surrounding the mine.
From the above-mentioned facts, I am inclined to believe that the exposed strata of the Kimberley mine extends from below the carboniferous in the primary rocks to the triassic in the secondary rocks, of course excluding the tufa and red sand, which would be much more recent, and from which I have not heard of any fossils being found.
[PLATE IV.]
Fig. 1. This shows a transverse section of a fragment of lignite found in the Kimberley mine, in Claim 165, at a depth of 140 feet, and embedded in “blue ground” or diamondiferous soil. Color, jet black.
a.a. Junction of two annual layers, or rings.
b.b. Fissure through medullary ray.
c.c. Portion of medullary ray.
Average of internal diameter of tubes, ¹⁄₁₀₀₀ inch.
Internal diameter of large tube, ¹⁄₈₀₀ inch. Number of layers from outside to centre of stem from which the section was taken, 48; and the remains of the bark still adhering to the specimen, ¼ inch thick. The above was drawn on Sept. 18th, 1877, by Mr. Geo. Jas. Lee, F. R. Met. Soc.; F. R. M. S., with the aid of neutral tint glass, 10 inches from the paper, and with ½ inch object glass, and A, eye piece, and magnified 121½ times, but here reduced to about 82.6 times.