60 
1122 of which 38 are still living, and 
1084 extinct (or unknown). 
239 of which 12 are still living, and 
227 extinct (or unknown). 
332 
49 
1742 
Number of species, Paris , 
London , 
Valognes . 
Belgium . 
By subtracting from these locali- 
ties the number of analogous 
species . . . . 504 
The real number of species of 
this epoch is . . . 1238 
The number of fossils of this period identified with living species is 42, 
which is to 1238 in the proportion of 3^ in 100. The number of fossil 
species which pass from the Eocene into the two other periods is 46, 
that is to say, in nearly the same proportion as the living analogues. 
Among the fossil species, four only are common to the three epochs, 
which are the following : — 
1 Dentalium coarctatum. 3 Bulimus terebellatus. 
2 Tornatella inflata. 4 Corbula complanata. 
The 42 other fossil species, which go no farther than the Miocene 
epoch, are distributed in the following manner : — 
Bordeaux and Dax . . 
Turin 
Angers 
Ronca 
Bordeaux, Dax and Touraine 
ib. ib. and Turin 
ib. ib. Touraine and Angers . 
ib. ib. Turin, Vienna and Baden 
ib. ib/ Touraine, Turin, Vienna and Angers 
ib. ib. Touraine, Vienna, Angers and Baden 
Turin and Ronca .... 
Angers and Ronca . 
17 
3 
2 
i 
4 
1 
2 
1 
1 
I 
2 
1 
42 
Of the 42 living species, the following 13 are common to the three 
epochs,— 
Dentalium entalis, 
strangulatum, 
I 
2 
3 
4 
5 
6 
Fissurella grseca, 
Bulla lignaria, 
Rissoa cochlearella, 
Murex fistulosus, 
7 Murex tubifer, 
8 Polymorphina gibba, 
9 Triloculina oblonga, 
1 0 Lucina divaricata, 
11 gibbosula, 
12 Isocardia cor, 
13 Nucula margaritacea, 
