Pa 
Math, Naturwiss. Classe, Pee 369. 1894. 
48 
Lett. ed. Art. (III.) 3: 769, 1858, and later both leaves and 
fruit were figured in “ Specimen Photographicum,” 97. p/. 40. figs: 
2, 3, 1859, but I have unfortunately not had access to these works. 
The exact geologic age of the Bridgeton sandstone has not 
been definitely settled, but it evidently represents late Tertiary or 
Pleistocene, containing a flora which is almost identical, in both 
species and genera, with that of the latitude of Virginia at the 
present time. 
The main point of interest in connection with these pods is that 
whereas their former companions are yet represented, both in 
genera and species, in the living vegetation of the region, the 
genera to which they are referred are no longer to be found there, 
but are elements in a more tropical flora. The fact that I have 
been unable to compare them satisfactorily with living species 
would indicate, taken in connection with the other circumstances 
of their occurrence, that they represent the last struggle for life of 
these genera in this latitude, due to the changing climatic condi- 
tions which preceded the advent of the Ice Age. Previous to 
that time they were widely distributed throughout both conti- 
nents. The north temperate species were obliterated, and only 
those which existed further south were able to continue their ex- 
istence. This supposition is also strengthened by the reference of 
the fossil species found further south to the living Lonchocarpus 
latifolius. : 
The facts in regard to the past history and distribution of these _ 
genera are of the utmost significance when taken in connection — 
with their present distribution. Several of the problems of their 
present distribution would be exceedingly difficult of explanation _ 
if we did not have these facts to guide us. The improbable 
theory of migration in recent times is no longer a necessary one, 
and we are led to the rational conclusion that genera, the species 
of which are now widely separated in different portions of the 
earth, were formerly of universal distribution but have become 
extinct over many wide areas where they formerly existed, due to 
changes in environment.* 
| 
* In this connection see “ Zur Theorie der Entwickelung der jetzigen Floren der 
Erde aus der Tertiarflora.” C, F. von Ettingshausen. Sitzb. Wien ~~ Wiss. = 
