STEVENSON— INTERRELATIONS OF THE FOSSIL FUELS. 149 



entered when the surrounding mass had already become peat. They 

 show no sign of compression. Some fragments of stems show the 

 great lacunae characteristic of plants belonging to a moist habitat. 

 The great variety in the plants suggests that the deposit is a typical 

 Waldtorf, which accords with the belief that the brown coals were 

 deposited as Waldmoors. 



Von Giimbel-"*' examined the Blatterkohle obtained near Bonn. 

 After treatment with Schultze's reagent, it showed under the micro- 

 scope only scattered plant cells, exines of pollen, algas-like clumps and 

 some very indefinite particles, which appear to correspond to bits of 

 animal matter. The descriptions by Horner, v. Giimbel and Heusler 

 show that Blatterkohle is of sapropelic origin and that it is wholly 

 similar to Lebertorf. 



De Serres-"' described Oligocene brown coals in southern France. 

 At the important gypsum quarries of Lac, near Narbonne, he ob- 

 served that between the beds of gypsum there are others, marly and 

 containing remains of plants and fishes, the latter being freshwater 

 forms. Dysodil, like that of Sicily, occurs in layers between thick 

 beds of marl overlying the gypsum. It is typical, in paper-thin 

 laminae and burns quickly with an abominable odor. Between the 

 laminae are enclosed imprints of fishes and plants, the latter appar- 

 ently dicotyledonous. The number of fishes is prodigious ; there are 

 not merely imprints, there is even the actual substance, at times, in 

 the marl beds and between the dysodil laminae. The lower part of 

 the section is mostly a limestone mass with lignites (brown coal). 

 The succession near Caunnette is r ( i ) Calcareous sandstone, belong- 

 ing to the compact gray macignos, exploited at Carcassone, 40 to 50 

 meters; (2) freshwater limestone, fissile, whitish, without trace 

 of organisms; (3) limestone, very compact, with many fluvia- 

 tile shells, Lymncra and Planorbis being most abundant, 10 to 20 

 meters ; (4) argillaceous limestone, allied to the macignos, 2 to 4 

 meters; (5) very bituminous freshwater limestone, divided by thin 

 layers of hard, black, lustrous lignite, 10 to 12 meters; (6) carbona- 

 ceous shale, blackish, " nerf " of the workmen, contains numerous 



-0^ C. W. V. Giimbel, " Beitrage," etc., pp. 146-148. 



20" M. de Serres, " Observations geologiques sur le Departement de 

 I'Aude," Soc. dcs Sci. Lille, 1835, pp. 439-471. 



