NUMMULITIC FORMATION. 
211 
j)osed by him to be related both to the bear and to the Kin- 
kajou (Cercoleptes). This creature appears to be the oldest 
known tertiary mammifer. 
Nummulitic Formation of Europe, Asia, etc. —Of all the 
rocks of the Eocene period, no formations are of such great 
geographical importance as the Upper and Middle Eocene, 
as above defined, assuming that the older tertiary formation, 
commonly called nummulitic, is correctly ascribed to this 
group. It appears that of more than fifty species of these 
foraminifera described by D’Archiac, one or two species only 
are found in other tertiary formations whether of older or 
newer date. Niimmidites intermedia^ a Middle Eocene form, 
ascends into the Lower Miocene, but it seems doubtful 
whether any species descends to the level of the London 
clay, still less to the Argile plastique or Woolwich beds. 
Separate groups of strata are often characterized by distinct 
species of nummulite; thus the beds between the lower Mio¬ 
cene and the lower Eocene may be divided into three sec¬ 
tions, distinguished by three different species of nummu- 
lites, N, variolaria in the upper, W Icevigata in the middle, 
and W planidata in the lower beds. The nummulitic lime¬ 
stone of the Swiss Alps rises to more than 10,000 feet above 
the level of the sea, and attains here and in other mountain 
chains a thickness of several thousand feet. It may be said 
to play a far more conspicuous part than any other tertiary 
group in the solid framework of the earth’s crust, whether 
in Europe, Asia, or Africa. It occurs in Algeria and Moroc¬ 
co, and has been traced from Egypt, where it was largely 
quarried of old for the building of the Pyramids, into Asia 
Minor, and across Persia by Bagdad to the mouths of the 
Indus. It has been observed not only in Cutch, but in the 
mountain ranges which separate Scinde from Persia, and 
which form the passes leading to Caboul; and it has been 
followed still farther eastward into India, as far as eastern 
Bengal and the frontiers of China. 
Dr. T. Thompson found nummulites at an elevation of no 
less than 16,500 feet above the level of the sea, in Western 
Thibet. One of the species, which I myself found very 
abundant on the flanks of the Pyrenees, in a compact crys¬ 
talline marble (Fig. 223) is called by M. d’Archiac ’ 
lites Puschi. The same is also very common in rocks of the 
same age in the Carpathians. In many distant countries, in 
Cutch, for example, some of the same shells, such as Nerita 
conoidea (Fig. 222), accompany the nummulites, as in France. 
The opinion of many observers, that the bTummulitic forma¬ 
tion belongs partly to the cretaceous era, seems chiefly to 
