MARYLAND GEOLOGICAL SURVEY 149 



In the Sunderland formation the specimens consist entirely of leaf 

 impressions in well-defined layers, apparently having been deposited in 

 still waters, their inclusion in limited numbers being merely incidental in 

 connection with the accumulation of inorganic sediments. In the Talbot 

 formation, on the other hand, the specimens consist of more or less well 

 preserved remains of leaves, seeds, fruits, twigs, branches, logs, and 

 stumps, included in masses of vegetable debris or deposits of finely com- 

 minuted vegetable matter, in which inorganic matter is present in rela- 

 tively small amounts. The first indicates inorganic sediments laid down 

 in quiet waters into which a few vegetable remains were accidentally car- 

 ried. The second represents, very largely, the accumulation of vegetation 

 in place, in swamps, lagoons, or estuaries, in which inorganic sediments 

 were occasionally transported and deposited. The specimens from the 

 Sunderland localities were comparatively easy to develop as the matrix 

 usually split along the bedding planes containing the leaf impressions, 

 but those from the Talbot formation were secured by allowing the masses 

 of peat or silt to disintegrate in pans of water, drying the skimmings 

 and settlings and sifting through graduated sieves, after which the ma- 

 terial was gone over with a hand lens. Acknowledgment is due to Mr. 

 P. H. Hillman, of the Seed Laboratory, TL S. Department of Agricul- 

 ture, for the determination of the smaller fruits and seeds. 



THE ELEPHANTS OF THE PLEISTOCENE 



BY 



Frederic A. Lucas 



Mammoth bones were described as long ago as 1696 by a Eussian 

 named Ludloff who gave them the Tartar name of " Mamatu ," so-called 

 by the Siberian peasants because they believed the bones to be those of 

 a gigantic mole which perished when exposed to the light, the name sig- 

 nifying " ground-dweller." No one had ever seen one, but the tusks and 

 bones were more or less common. Thus the inference was quite natural 

 that the beast dwelt underground since it had never been seen above 



