570 Reports and Proceedings—Greological Society of London. 
described the mode of occurrence of each of these, and their reiations, 
the serpentine being almost certainly intrusive in the schist, and the 
gabbro in the serpentine. The microscopic structure of the various 
rocks was described in detail, especially of the last. It presents the 
usual characteristics, and is an altered olivine rock which has con- 
tained bronzite. One or two varieties are rather peculiar; an 
ophicalcite and a compact chloritic schist containing chromite are also 
noticed. At Porthdinlleyn there is no serpentine, but a remarkably 
interesting series of agglomerates and (probably) lava-flows of a 
basic nature, which may now be denominated diabases. 
2. “Note on the Occurrence of Remains of Recent Plants in 
Brown Iron-ore.” By J. Arthur Phillips, Esq., F.G.S. 
The fossilizing ironstone described by the author occurs at Rio 
Tinto, in the province of Huelva, Spain, in close proximity to the 
celebrated copper-mines of that name, where it forms a thick hori- 
zontal capping of a hill known as the Mésa de los Pinos. In this 
iron-ore Mr. Carruthers has identified the following vegetable 
remains :—Leaves and acorns of Quercus ilex, Linn.; leaves and 
seeds of a two-leaved species of Pinus, most probably Pinus pinea, 
Linn. ; the cone of Hquisetum arvense, Linn. ; and a small branch of 
a species of Hrica. There is also a well-marked leaf of a Dico- 
tyledonous plant not yet identified. A great portion of many of the 
specimens consists of a thick growth of moss; but it is impossible 
to say what the species are. The whole is permeated with minute 
branching roots, showing that the vegetation was formed asa great 
mass, the oak- and pine-leaves having been probably carried or 
blown into it. The plants are evidently all of the same species as 
are still growing in Spain. 
The author attributes this deposit of ironstone to the decomposi- 
tion, partly by organic agency, of ferruginous salts, derived from the 
oxidation of iron pyrites, which flowed into a marsh or shallow 
lagoon. Subsequently to this the valleys of the Rio Agrio and Rio. 
Tinto were eroded, leaving the Mésa de los Pinos with its thick 
capping of iron-ore. 
The very recent character of this deposit is evident from the 
fossils it contains; but the erosion of the valleys certainly took 
place before the Roman occupation of the district. This is satis- 
factorily shown not only by the position of various remains of that 
date, but also by the fact that the Roman grave-stones, which are 
still remaining in the locality, are made of this ironstone. 
3. “Notes on the Locality of some Fossils found in the Carboni- 
ferous rocks at T’ang Shan, situated, in a N.N.E. direction, about 
120 miles from Tientsin, in the province of Chih Li, China.” By 
James W. Carrall, Ksq., F.G.S. With a Note by Wm. Carruthers, 
Esq., F.R.S., F.G.S. 
The author described the locality from which he obtained some 
plant remains of apparently Carboniferous age, and stated that 
mining-operations had been carried on by a Chinese company in the 
district simce the year 1878. Several seams of coal occur, varying 
in thickness from 11 inches to 6 feet. Mr. Carruthers stated in a 
