SCIENTIFIC SUMMARY. 
499 
Connemara ; and reposing on these, and passing underneath the gneissic 
strata, is a hand of serpentinous limestone, the structure of which is not of 
animal origin, but results solely from mineral association. The gneissose 
rocks on the north are covered unconformably by sandstones, the fossils of 
which indicate the horizon of the Upper Llandovery rocks. These meta- 
morphic rocks correspond with those of the Highlands of Scotland, represent- 
ing the Upper Quartz rocks, upper Limestone, and Upper Gneiss, the 
positions of which are known in consequence of the Lower Limestones at 
Durness having been determined to be not lower than the Llandeilo Flags. 
The Bohemian Gneiss and the Eozoon. — A very important memoir by 
Professor Hochstetter has been read before the Vienna Academy of Sciences. 
The Professor gives in the first instance a sketch of the discoveries in Ireland 
and in Canada, and then proceeds to discuss the relations of the Bohemian 
gneiss. This he describes as consisting of two great series 'of gneissose and 
granitic rocks, great enfoldings of which form the mountain-range of the 
Bohmerwald. The lower (1) is Giimbel’s “ Gojic Gneiss,” and the upper- 
series (2) is his “ Hercynian Gneiss ; ” this latter contains (like the Laurentian 
Gneiss of Canada) beds of graphite and of serpentinous marble. Pebbles of 
quartz in it, and its bituminous odour when struck with a hammer, had 
already satisfied Dr. Hochstetter of the sedimentary character of the marble ; 
and he sent some of the green variety (from Krummau) to Dr. Carpenter, who 
determined the presence of Eozoon in it. The upper gneiss is succeeded 
unconformably by (3) mica-schist, here referred to the Upper Laurentian ; 
this by (4) clay-slates ; and (5) the “ Przibram schists ” (with Annelid- 
marks, — Fritsch ), which are tabulated together as equal to the Lower 
Cambrian or Longmynd rocks of Britain, and the Huronian of Canada. In 
the diagram, however, No. 4 is conformable to No. 3 ; but there is a violent 
unconformity between No. 4 and No. 5. The Przibram grauwacke follows 
next, and, with the “ Ginetz beds ” (or “ Primordial beds ” of Barrande), is 
grouped as the Upper Cambrian of Britain, and the Taconic beds, or Potsdam 
sandstone, of North America. 
• Historical Researches on the Stone Age. — This is a subject which has 
recently engaged the attention of M. Chevreul, who has been delivering some 
. essays upon it before the French Academy. The French chemist has brought 
the light of Chinese literature to bear upon the problems of the “ Stone 
Age,” and has discovered in ^certain 'writings of the date of 1122 b.c. 
distinct allusions to the use of arrows pointed with stone. Having communi- 
cated the fact of this discovery to M. Stanislaus J ullien, that gentleman 
stated that in recently digging in the ruins of an ancient Chinese fortress 
stone-headed arrows were found in abundance. 
The Geology of Mount Sinai. — A highly interesting paper upon the geology 
of this mountain was read before the Geological Society at one of its late 
meetings, by the Rev. W. Holland. Mr. Holland describes the physical 
features of the peninsula as being in the north an extensive plateau of creta- 
ceous limestone, bounded on the south and underrun by a mountain-range 
compound of schists, porphyries, and syenite. Near Jebal Serbal is a moun- 
tain of Nummulitic limestone ; and a limestone apparently of more recent date 
occurs near Tor and Ras Mohammed. The author further stated that in some 
parts of the peninsula the syenite mountains are capped by a considerable 
