1G8 THE GEOLOGIST. 
it is become impossible to procure it. At times the topaz is decomposed, and 
then it is knowTi under the name of "rotten topaz." 
The ores of tellurium are met vrith. at Saint Joze d'Elrei, and near Saint 
Yincent, between Ouro Preto and Morro Velho; moreover, there is some 
native brimstone in a vein of quartz near Saint Joze. 
The crystalline schists of Morro Velho and of Sabarra contain fine crystals 
of carbonate of lime, of arragonite, of magnetic iron-pyrites, of copper-pyrites, 
of manganese-ore ; in those of Congonhas there is chromate of lead. 
Arsenical pyrites are observed in the quartz at Ouro Preto, Morro Velho, 
and Antonio Pereira. 
Scorodite, pseudomorphs of hemonite after the scorodite, and scorodite after 
arsenical iron, are found in the crystalline schist, and in the " tapanhoacanga" 
of Passagem and Antonio Pereira. The amethyst forms in vems in the crys- 
talline schist and in the gneiss. 
The chrysolite, cymophane, green and transparent tourmaline collect in the 
cascalho of the rivers which traverse the crystalline schist near Kalihao. 
The American river and the Pianhy seem to be the richest ; the first is no 
longer worked, but for twenty leagues along the road to Kalihao it seems to 
have been entirely excavated ; it is in the river Pianhy that the chrysolite is 
found, which is employed in clock -making and in jewellery. The transparent 
andalusite is also brought from one of these two rivers. Among the various 
minerals that are found in the cascalho of Brazil, we can mention, as does also 
M. Damour, disthene, felspar, precious garnet, hydrophosphate of aluminum, 
phosphate of yttria, pure and titaniferous, diaspore columbite, Baierine, oxide 
of pewter, cinnabar, and graphite. 
Gold is everywhere found in the region of the diamond-bearing schists, and 
there is also platinum ; these metals remain upon the vatee with the other ores 
that the washing separates from the diamonds. — Translation of a Paper read 
before the Geological Society of Berlin. By MM. Ch. Heusser and G. Clarez, 
Tvith mineralogical notes by G. Pose (Ann. des Mines, vol. xvii., part 2 of 1860. 
Silurian Strata, near Cardiff. — Dear Sir, — In your Januaiy number 
there was a notice of " Murray's Handbook for South Wales." In the notice 
of places of geologic interest appended to that book there is an omission I should 
like to supply. A short time since I was residing at Cardiff, on the borders of 
Glamorganshire, and in my walks about the neighbourhood discovered a quarry 
in what seemed to me to be the Upper Silurian formation. This quarry is 
situated on a hill-side about two miles east of Cardiff, at a place called Pen-y-lau, 
and from the mouth of the quarry there is a beautiful view of the Bristol 
Channel and the opposite coast. Tracing the course of some brooks in the 
neighbourhood, I found the same kind of rock extended for some distance round 
the side of the hill. The quarry I found to be very full of fossils. Shells were 
in abundance. Amongst others I have a BelleropJion dilatatus, and an Athyris 
tumida, with the internal spiral processes in a beautiful state of preservation. 
Corals also were in abundance, though not so much so as shells and trilobites : 
of the latter I found perfect specimens of Illanus Barriensis, two kinds of 
Acidaspis, Calymene Blumenbachii, Encrinurus ptmctatus, Phacops caudatus, 
Phacops ( caudatus) Leryi, and Phacops Stokesii, and a head and tail of Ckeirurus 
himucronatus. 
I have also out of the same quarry a large head of Phacops caudatnsy in one 
eye of which sixty two spherical lenses still remain. This specimen was pre- 
sented to me by Mr. J. B. Tliomas, of Cardiff, who is the only local geologist. 
Believing on the above evidence the rock in question to be Silurian, I was 
surprised to find it mapped in the Geological Ordnance Survey as Old Bed 
Sandstone. I therefore communicated the fact to Sir Roderick Murchison, 
and at his request sent him my fossils, when after they had been examined by 
