152 



PREHISTORIC EUROPE. 



of certain variegated red sandstones which are common in that 



region. 



The loss almost invariably rests upon gravel. This is the 

 rule in valleys, and these gravels are unquestionably of fluvia- 

 tile origin. They are indeed of the same age and origin as the 

 ancient river-gravels of Northern France, and have, like them, 

 yielded numerous remains of the old mammalia, as at Mosbach 

 near Biebrich, and Schierstein. More than this, we find that the 

 fauna comprises representatives from all the three groups — 

 northern, temperate, and southern. Now and again valley-loss 

 is underlaid by a kind of lignite or brown coal. Here, for 

 example, is a section of the loss and lignite-beds of Steinbach 

 near Baden-Baden, as given by Dr. F. Sandberger : — * 



Feet. Inches. 



Section, 200 feet above Rhine. 



1. Loss with. Helix arbustorum, and its var. alpestris, 



Helix hispida, Pupa doliuin, P. columella, P. 

 muscorum, Clausilia dubia, Succinea oblonga 



2. Coarse sand . 



3. Yellow loam or clay . 



4. Coarse sand . 



5. Yellowish gray clay . 



6. Light grayish blue clay 



7. " Moor coal," with leaves, trunks, and branches 



of Betula pubescens, seeds and leaves of Men- 

 yanthes trifoliata . 



But when the loss is followed to levels higher than those 

 reached by the highest valley-gravels, it may come to rest 

 directly upon glacial deposits. 



The loss of the French river-valleys has a general resem- 

 blance to that of the Khine and other valleys of Central Europe. 

 And this is more particularly the case with the Bhone, as we 

 might have expected. In the north of France the loss, while 

 retaining the character of a sandy calcareous loam, yet frequently 



1 "Geol. Beschreibung der Gegend von Baden-Baden," Beitr. z. Statistik der 

 innern Verw. d. Grossh. Baden, Heft. xi. p. 7 ; Die Land- und Susswasser-Conchy- 

 lien der Vorwelt, p. 761. 



