| → 
a
10
,
 1859 1860 1861 1866 1869 | 
| 
a
10
,
 1872 | 
  | 
| → 
m
6
,
 1859 1860 1861 1866 1869 | 
| 
m
6
,
 1872 | 
  | 
| → call 1859 1860 1861 1866 1869 | 
| consider as intermediate 1872 | 
  | 
| → together, intermediate in character, 1859 1860 1861 1866 1869 | 
| OMIT 1872 | 
  | 
| → justified, as 1859 1860 1861 1866 1869 | 
| partly justified, for 1872 | 
  | 
| → families 1859 1860 1861 | 
| of the families (those 1866 1869 1872 | 
  | 
| → 
a
14
,
 1859 1860 1861 1866 1872 | 
| 
a
14
,
 1869 | 
  | 
| → 
b
14
,
 1859 1860 1861 1866 1872 | 
| 
b
14
,
 1869 | 
  | 
| → 
the two other families (namely,
a
14
to
f
14
now including five genera, and
o
14
to
m
14
) would yet remain distinct.
 1859 1860 1861 | 
| there would remain two families, which would be less distinct from each other than they were before the discovery of the fossils. 1866 1869 1872 | 
  | 
| ↑ 1 blocks not present in  1859 1860 1861 1866; present in  1869 1872 | 
|  So again, 
if the three families formed of eight genera 
(
a
14  
to 
m
14
),  on the uppermost line, be supposed to differ from each other by half a dozen 
important characters, then the families which existed at the period marked VI. would certainly have differed from each other by a less number of characters; for they would at this early stage of descent have diverged in a less degree from their common progenitor. 
 | 
  | 
| → If, for instance, we suppose the existing genera of the two families 1859 1860 1861 | 
| 
So again, if the three families formed of eight genera (
a
14,
to
m
14
), on the uppermost line, be supposed
 1866 | 
  | 
| → a dozen characters, in this case the genera, 1859 1860 1861 | 
| half a dozen important characters, then the families which existed 1866 | 
  | 
| → differ 1859 1860 1861 | 
| certainly have differed from each other 1866 | 
  | 
| → at 1859 1860 1861 | 
| they would at 1866 | 
  | 
| → character from the 1859 1860 1861 | 
| a less degree from their 1866 | 
  |