580 STEVENSON— FORMATION OF COAL BEDS. [November 3. 



tity of pollen. Two specimens from other localities agree in that 

 the cross-section shows a comparatively dense mass of boghead-like 

 material, deep brown in color. One contains well preserved remains 

 of leaves and other organs and the other contains some freshwater 

 mollusks. The granular, felt-like mass, treated with reagents, breaks 

 up and then one sees fragments of woody material, seeds, mosses, 

 and above all pollen grains, several thousands to the cubic milli- 

 meter. This substance bears remarkable resemblance to cannel. 



Blattertorf, so named from its foliated structure, is closely allied 

 toLebertorf. v. Giimbel has described a specimen from thekurishen 

 lowland south from Nidden. This mass, in extraordinarily thin 

 lamina?, is composed of numerous bright lamellae alternating with 

 dull layers, recalling by their luster, pitch and glance coals. The 

 bright material comes from ribs and the harder parts of plants, the 

 grass leaves, which compose the chief mass. Along with those are 

 bits of moss, bast fibers, etc., in the felt-like mass, as well as an 

 astonishing number of pollen granules. 



The results of Friih's'^^ studies were published in the same year 

 with those of v. Giimbel. His conclusions respecting the composi- 

 tion of Lebertorf differ somewhat from those reached by v. Giimbel. 

 One rarely finds in ordinary peat any remains of freshwater algae. 

 But Friih finds that those algiT do not tlecompose so readily as one 

 might imagine ; yet in the ordinary peat they are only rare and acces- 

 sory constituents, never occurring in such quantity as to be impor- 

 tant elements. At the same time there are types of which they are 

 essential constituents. 



The Febertorf, found in ponds within Prussia, as the basis of 

 the Rasenmoor at Purpesseln and as basis of a Hochmoor at Gum- 

 binnen, is a liver-brown gelatinous mass. That from Jakobau, in 

 west Prussia, consists chiefly of algae, there being more than 60 spe- 

 cies of Chroococcaceae, Plydrodictea? and Diatomacere, with which 

 are found indefinite remains of mosses along with pollen of Pinns 

 and Coryhis. The Torfschiefer of E. Geinitz from Gustrow has a 

 very similar composition. The typical Pebertorf from Purpesseln 

 has recognizable colonies of Macrocystis, while that from Niederwyl 



"J. J. I'Viili, " Ue1)cr Torf und Dopplcrit," Trogen, 1883. p. 20. 



178 



