436 cash: fossil fructifications of yokkshire coal measures. 
equivalent bed at Oldham and elsewhere in Lancashire, of the Scotch 
beds at Laggan Bay in the island of Arran, at Burntisland, in 
Fifeshire, of the coal measures of WestphaUa, of Aloravia, and of 
Barnat in S. Hungary, as well as of the silicified specimens from 
St. Autun and St. Etienne in France, have yielded rich and precious 
material, which has thrown a flood of light upon an exceedingly 
difficult department of palaeobotany, for it was only when the delicate 
organs of fructification were discovered with their minutest structures 
intact that the consequent rapid advance in our knowledge of this 
department bscame possible. 
In Yorkshire, through the energetic and intelligent labours of 
Messrs. Binns, Butterworth, and Spencer, many interesting forms have 
been discovered and described, and especially by the long-continued 
and invaluable researches of Dr. W- C. "Williamson, has this depart- 
ment of palaeobotany been again and again enriched. 
The chief fossil fructifications of the Yorkshire coal measures 
are Lepidostrobi or fruit cones of Lepidodendron of several species, 
the true fructification of Calamities. (Williamson : Memoirs of the 
Literary and Phil. Society of Manchester, 1869-70.) Bowmanites 
(Volkmannia) Dawsoni, probably the fruit of Asterophyllites. 
(Williamson: Memoirs of the Literary and Phil. Society of Man- 
chester, 1870-7L) Several sporangia of ferns, and the fruits of 
numerous Gymnospermous plants, (Cardiocarpon, Lagenostoma, 
Trigonocarpon, &c.) Li addition to those now enumerated there are 
many sporecases, &c., (Sporocarpon, Traquaria, Zygosporites, &c.), 
which are as yet of doubtful affinities . 
The state of preservation in which these fructifications occur is 
very remarkable, the cells of which the organisms are built up have 
been infiltrated with transparent carbonate of lime, the cell-walls 
have been mineralised, and when the fossils are found fairly free from 
iron pyrites, they may be cut by the aid of the lapidary's wheel into 
slices, which can be attached by Canada balsam to slips of glass, and 
then ground down sufficiently thin and transparent for micros- 
copic examination ; under a low magnifying power they display all 
details as perfectly as sections cut from a living plant, and under the 
higher powers are seen to exhibit a perfection of structure even in their 
