184 NATURAL SCIENCE. MarcH, 
and Pethathali encamping ground above Silakank (19,265 English 
feet), to\Sirkia River in Hundes ; a complete section from (Cambrian ?) 
Haimantas to the Gieumal Sandstone (Cretaceous), without a great 
discordance, gives, according to Dr. Griesbach :— 
Haimantas At, fe Be £. ae 3,000—4,000 feet. 
Lower Silurian .. tie a ots ete 200 is 
Upper Silurian .. sie i BA ie I,100 ¥ 
Devonian.. oe 3c 20 aC a0 700 sn 
Carboniferous .. 5 oe Ae ake I,200—I,400 ,, 
Permian and Trias ae us sie os 3,600—3,g900 ,, 
Lias and Spiti Shales .. ae re Ge 1,400? a 
Gieumal Sandstone .. Bs os ts I,200—I,500 ,, 

12,400—1I4,200 feet. 
The determination of the thickness of the Spiti Shales and Gieumal 
Sandstone is difficult, because these less-resistent beds are crumpled 
into local folds. 
A parallel section across the Kurkutidhar range (Chor Hoti, 
about 18,000 feet), Shalshal encamping ground and Shalshal Pass 
(16,390 feet) to Hundes gives, without the Haimantas :— 
Silurian .. 3 ee as ae as I,200—1,400 feet. 
Devonian and Carboniferous .. a se 1,800—2,300 ,, 
Permian and Lower Trias .. 35 és 200 FF 
Middle Trias .. ste ee a is 100 a 
Upper Trias to Dachstein Limestone 36 1,400 - 
Dachstein Limestone, Rhetie and Lias_ .. 2,200 a 
Spiti Shales ae at ate 30 +6 1,000 ? ia 
Gieumal Sandstone .. as Se ae 1,500? mt 

9,400—Io, 100 feet. 
These figures show that a great and deep ocean has been incorporated 
into the continent, and that the deposits of this ocean form part of the 
highest mountain ranges. 
It may be remarked that within the eastern Alps Mesozoic lime- 
stones of different ages contain deep-water radiolarian chert. But 
the great and well-bedded masses of white Rhetic limestones of 
Austria betray distinct proofs of a continuous rising of the shore-line. 
It is also true that certain bright red enclosures within these white 
limestones seem clearly not to be red deep-sea clay, but true terra rossa, 
formed by atmospheric decomposition of the limestone; so that these 
beds must have formed reefs in the ocean. Therefore it is at present 
difficult to say whether in the Alps the Tethyan Ocean did at any 
time attain the total depth of, say, 2,000 fathoms ; or whether deposits 
followed so rapidly and depression was so continuous that this was 
not the case. 
The later Tethyan history, the recapitulation of the vicissitudes 
which led to the formation of the existing Mediterranean, forms 
certainly one of the most attractive chapters of historical geography. 
Marine deposits of Mediterranean type (Erste Mediterranstufe, 
Miocéne inférieur) enter the Rhone Valley, surround the present site 
