220 
ELEMENTS OF GEOLOGY. 
Fig. 139. 
and many other plants. The ancient lake seems to have 
had a belt of poplars and willows round its borders, count¬ 
less leaves of which were imbedded in mud, and together 
with them, at some points, a species of reed, Arundo^ which 
was very common. 
One of the most characteristic shrubs is a papilionaceous 
and leguminous plant of an extinct genus, called by Heer 
Fodogonium^ of which two species are known. Entire twigs 
have been found with flowers, and always without leaves, as 
the flowers evidently came out, as in the poplar and willow 
tribe, before any leaves made their appearance. Other spec¬ 
imens have been obtained with ripe fruits accompanied by 
leaves, which resemble those of the tamarind, to which it 
was evidently allied, being of the family Csesalpineae, now 
proper to warmer regions. 
The Upper Miocene flora of CEningen is peculiarly impor¬ 
tant, in consequence of the number of genera of which not 
merely the leaves, but, as in the case of the Fodogonium just 
mentioned, the fruit also and even the flower are known. 
Thus there are nineteen species of maple, ten of which have 
already been found 
with fruit. Although 
in no one region of the 
globe do so many ma¬ 
ples now flourish, we 
need not suspect Pro¬ 
fessor Heer of having 
made too many species 
in this genus when we 
consider the manner in 
which he has dealt with 
one of them, Acer trilo- 
Figs. 139, 140. 
Of this plant the num¬ 
ber of marked varieties 
figured and named is 
very great, and no less 
Acer trilohatum, normal form; Heer, Flora Tert. than three of them had 
Helv,, PI. 114, Fig. 2. Size diam. (Part only of Vippn na rlici- 
the long stalk of the original fossil specimen is here uu db uib 
given). Upper Miocene, (Eningen; also found in tinct SpecieS by Other 
Lower Miocene of Switzerland. ^ ^ ^ botanistS, while six of 
the others might have laid claim, with nearly equal proprie¬ 
ty, to a like distinction. The common form, called Acer tri- 
lohatum^ Fig. 139, may be taken as a normal representative 
of the (Eningen fossil, and Fig. 140, as one of the most diver¬ 
gent varieties, having almost four lobes in the leaf instead 
of three. 
