RED RIVER SOR THE AORT H. 181 
They are, Favosites basaltica ; Coscinopora sulcata ; hemispherical masses of Syringo- 
pora; Cheetetes lycoperdon ; a Conularia ; a small, beautiful undetermined species of 
Pleurorhynchus ; Ormoceras Brongniarti ; Pleurotomaria lenticularis(?) ; Leptena alter- 
nata ; Lepteena plano-convexa(?); Calymene senaria ; and several specimens of the 
shield of J/lcenus crassicauda. Many of these are identically the same fossils which 
occur in the lower part of F. 3, in Wisconsin and Iowa, in the blue limestones of 
Indiana, Ohio, Kentucky, and Tennessee, and also in the Lower Silurian of Europe. 
The Coscinopora is precisely the same as the coral which is particularly charac- 
teristic of the lower beds of the Upper Magnesian Limestone of Wisconsin. The 
specimens of Fuvosites basaltica cannot be distinguished from those which abound in 
the Upper Magnesian Limestones of Wisconsin and Iowa, and the Lower Coralline 
beds of the Falls of the Ohio. It is also worthy of note that these limestones of Red 
River, like their equivalents in Iowa and Wisconsin, are highly magnesian, con- 
taining from seventeen to forty per cent. of the carbonate of that alkaline earth.* 
Being curious to know something of the climate of this part of Red River, I made 
many inquiries, relative to this subject, of the inhabitants; all of whom confirmed 
the previous idea I had received of the severity of their winters. I am happy, 
however, to be able to furnish something more definite, which will be interesting to 
the meteorologist. For the last two years a regular meteorological journal had been 
kept at the Lower Fort, by order of the British War Department, under the superin- 
tendence of the Hon. Captain Moody, of the corps of Sappers and Miners. That 
gentleman was so kind as to permit me to look over it, and, indeed, to make an 
abstract, and to copy a portion of it, for the months of January and February of 
1847, and June and July, 1848. 
The coldest weather which was known during the years 1847 and ’48, was on 
the night of January 20, 1847, when the mercury froze quite solid. On that night 
the spirit thermometer indicated, at the Lower Fort, —47° ; at the Upper Fort, —48°. 
To test the severity of the cold, some of the officers poured quicksilver into their 
* Two analyses, which Dr. Shumard made in my laboratory, and under my direction, yielded respec- 
tively as follows 
Compact limestone from Red River, containing Leptena :— 
Carbonate of lime, ; a : : : ; 53:7 
Carbonate of mies ; ; : : 40-5 
Insoluble matter, ’ : : : : ‘8 
Alumina, oxide of iron, and manganese, : : . 4 
Water and loss, : ; ; ‘ j : 1 
100: 
Spotted and banded limestone from Red River, containing Coscinopora :— 
Carbonate of lime, 78-1 
Carbonate of cei 17:8 
Insoluble matter, Le 
Alumina, oxide of iron, and hangar : Se 
Water and loss, 
