Geology and Natural History. 145 
with me, I could have marked the exact elevation above the 
valleys, ‘and observations made a widely separated localities 
In the valley of Champlain, J found seven distinct terraces 
from the water level up to 750 feet. I found Zellina Groenlandica 
in No. 1 and No, 4, the latter two hundred and fifty feet by esti- 
mate above the lake, 
2. Deep-sea chalky deposits but little magnesian.—The analyses 
which have been made of the chalky mud that has been brought 
up from the bottom of the Atlantic, have found but little ei 
i, 91) 
1°76 per cent to 58°80 of carbonate of lime. Besides these con- 
stituents, Hunter’s sualy found 23°36 silica with 5°31 of alumina, 
5° 91 of sesquioxide of iron, besides the above = 99°92; and Maho- 
ny’s, 26°60 silica, 3°80 sesquioxide and phosphate of ir on, with 4°20 
of soluble salts, 2°30 of organic substance, 2°50 water and 0°08 FeO. 
An analysis by C. W. Gtimbel (Jahrb. Min., 1870, 753) of a 
specimen stated to have been obtained in 29°37’ N. lat. and 18° 20’ 
. long., at a depth of 2,350 fathoms, and made after separating 
10 p. c. of foraminifers and large, organisms, and 1°3 of mineral 
stance, and 2°34 water and loss 
i Wenealites and Orbitolites in the Mesozoic, Belemnites 
the Rovens and Ammonites in the Carboni, erous.—GUMBEL had 
e 
names V. Jurassica, in the Jurassic beds of Franconia; also two 
species sa Orbitolites 0. a ursor Giimb, and O. circumval- 
lata the Lias of the vicinity of Rovensd (Jahrb. f. 
Min, , 1879, 341), although ‘in recently this genus ‘was unknown 
from rocks, below the Cretaceous. We now know also of Eocene 
belemnites— B. rugifer Schlen b.—from the Eocene of Ronca; and 
lately Mr. Waagen has discevered, in the Carboniferous formation 
of India, supposed to be = the Carboniferous age, true Ammo- 
nites, ey Oe Univ., May 15, 1878. 
ed o Ue the Rhine at the falls of Schaffhausen changed in 
r. WuR 
of the limestone, and only deposits of pebbles, indicating the site 
of an old N, rise and §.8.W. valley of erosion or river bed, nearly 
in the direc of the stream. The glacial cae ev -idently 
filled this ancient valley, and thus forced the riv m its course, 
Giving it a und south and west to a point Fliers: by a fall 
Am. Jour. Sor sgrsbte gens. Vou. VI, No. 32.—Aveust, 1873. 
