knowi/iox] TERTIARY PLANTS OF NORTH AMERICA. 11 
ures, but no attempt has been made to make it absolutely complete, 
since to have done this would have greatly increased the labor of com- 
pilation without adding much to its value as a catalogue. The original 
and, for sake of convenience, most important references are given. 
When the species is a foreign one the original reference is given, fol- 
lowed by a reference to the first place where it is recorded as belonging 
to our flora. Then follow the references to figures and descriptions, if 
there be any, relating to its North American history. 
The synonymy is placed in proper order under the species to which 
it belongs, Each synonym is, however, entered in its proper alphabet- 
ical place, followed by an indication of the form to which it is now 
referred. Thus: "Ficus ? fimbriata Lx.=Ereinophyllum fimbriatum." 
In the numerous reports on fossil plants published in the Annual 
Eeports of the Hayden Survey, Lesquereux described many species 
supposed to be new to science, and also identified numerous foreign 
species, that were never afterwards alluded to by him. There are prob- 
ably more than 100 species coming under this heading that are not 
entitled to recognition as belonging to our flora. These new or foreign 
species were described or identified from time to time in these prelimi- 
nary reports, but when Lesquereux came to study them more carefully, 
in preparing them for the final monographs, they were discarded or 
merged into other species, and no record was made of such disposition. 
They stand, therefore, in the books as valid species, while in reality 
they are hardly more than nomina nuda. The specimens upon which 
they were based are now lost or embraced under other names in such a 
way that there is absolutely no connection between them. In the fol- 
lowing catalogue these species have been indicated by a bracketed 
statement at the end. Thus: "Quercus Goldianus Lx., Ann. Eept. 
U. S. Geol. and Geogr. Surv. Terr., p. 898 (1873 [1874] ). [Not recognized 
by its author after first description.]" 
No attempt has been made in this catalogue to give an absolutely 
complete account of the geographical distribution of the various spe- 
cies. It would have required a monographic revision of each species 
to determine accurately its areal distribution, and such a work was not 
contemplated at the present time. The distribution here given is 
taken mainly from the books, with little or no revision, and while it is 
undoubtedly correct in a large majority of cases, it is not to be taken 
as absolutely so. One of the tasks of the future will be to work out 
more completely the geographical distribution of our flora. 
In similar manner, the geological distribution as here given is not to 
be taken as final. It is compiled from the books in most cases, and 
while it has been given as completely and as accurately as was possible 
under the circumstances, it is constantly changing to accord with the 
changes in the conception of the various geological horizons. As an 
example, the plant-bearing horizon at Point of Rocks, Wyoming, had 
always been referred to the true Laramie, until it was found, in 1896, 1 
See Stanton and Knowlton: Bull. Geol. Soc. Am.. Vol. VIII, pp. 127-150. 
