B E D RIVE E 0 F T H E N 0 R T H. 



181 



They are, Favosites basaltica; Cosdnopora sulcata; hemispherical masses of Syringo- 

 pora; Chcetetes lycoperdon ; a Conularia ; a small, beautiful undetermined species of 

 Pleurorhynchus ; Ormoceras Brongniarti; Plearotomarialenticularis^l) • Leptcena alter- 

 nate; Leptcena plano-convexaij) ; Calymene senaria ; and several specimens of the 

 shield of lllamus 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 Cosdnopora 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 Favosites 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 Leptcena : — 



Carbonate of lime, 

 Carbonate of magnesia. 

 Insoluble matter, 



Alumina, oxide of iron, and manganese, 

 Water and loss, 



Spotted and banded limestone from Red River, containing Cosdnopora : — 



53-7 

 40-5 

 •8 



4- 

 1 



100- 



Carbonate of lime, ....... 78*1 



Carbonate of magnesia, ...... 1 7*8 



Insoluble matter, . . . . 1- 



Alumina, oxide of iron, and manganese, .... 1-4 



Water and loss, . . . . . . .1-7 



100- 



