164 QUATERNARY PERIOD. 



Of the Vascular Cryptogamia Prof. Heer only knows the 

 jointed and striated stems of a species of horsetail (Equisetum 

 limosum, Linn. ?) . 



Although the number of plants hitherto found in the lignites 

 is not great; it is sufficient to enable us to form an idea of the 

 appearance of the vegetation of the peat-bogs at the time of 

 their formation ; and Prof. Heer believes that the flora must 

 actually have appeared very much as shown in the Plate of 

 Durnten. 



Characteristic forms of animals, the elephant, the rhinoceros, 

 and the Urus, are seen in the restored landscape ; and they 

 merit attention. 



Of the elephant two very beautifully preserved molars were 

 found at Durnten, together with fragments of large bones at the 

 bottom of the lignite. The grinding-surface in the back molar 

 of the lower jaw (fig. 350) is 67 millim. (or 2*638 inches) in 

 transverse diameter, and is traversed by twelve transverse 

 laminae, the enamelled edges of which are undulated, and here 

 and there form projecting angles. This is the tooth-structure 

 of Elephas antiquus, Falc., which appears to be most nearly re- 

 lated to the African elephant, and was very probably of the same 

 size and form. In the mammoth (Elephas primigenius, Blum., 

 fig. 351) the transverse plates run parallel, stand closer together, 

 are much less crenulated, and have no projecting points. 



Of the rhinoceros a nearly complete skeleton was found in 

 the clay of the lignite -deposit of Durnten ; but, by an unfortu- 

 nate accident, it was almost all lost. Nevertheless a number of 

 bones and some of the teeth reached Prof. Heer ; and these enable 

 him to recognize it as Rhinoceros etruscus, Falc. *. It differs 



* Hermann de Meyer regarded it as Rhinoceros Merkii. According to him 

 (see i Palseontographica/ vol. ix. 1864, p. 242) there were in Germany two qua- 

 ternary species of Rhinoceros : R. Merkii, in which the nostrils are separated 

 by a bony septum only in the anterior part of their extent, and of which the 

 molars are not surrounded by enamel j and R. tichorhinus, Cuv., with a com- 

 plete nasal septum, and molars furnished with a thick layer of enamel. The 

 existing and Tertiary species (as also the Pliocene species, R. leptorhimis, 

 Cuv.) have no long nasal septum; and their incisor teeth are persistent. R. 

 tichorhinus has been found frozen in the ground in Siberia, still retaining its 

 skin and hair j and its teeth and bones have been noticed in many parts of 



