10 CATALOGUE OF THE CRETACEOUS AND [bull. 152. 
of North America; 7 " a list under the same title in the following 
volume;- a " Table showing the geographical distribution of the fossils 
of the Laramie group, collected during the season of 1877 ;" 3 "A table 
of distribution of the plants of the Cretaceous Oenomanian formation ;" l 
"Table of distribution of the species of the Laramie group;" 5 "Table 
of distribution of the plants of the Green River and White River 
group ;" (i "Table of distribution of North American Miocene fossil 
plants;" 7 " Table showing the distribution of the plants of the Dakota 
group;" 8 Lester F. Ward: "Table of distribution of Laramie, Seno- 
nian, and Eocene plants," 9 etc. 
In the present catalogue the entire flora is arranged in a single alpha- 
betical sequence. This arrangement precludes the duplication of 
species which may occur in more than one formation, and is, moreover, 
easier of use than when the species are arranged according to botanical 
affinities. 
I have given for each genus the original date and place of publica- 
tion. In the case of the exclusively fossil genera much care has been 
expended in verifying these points, and while it is too much to expect 
that all are absolutely correct, it is hoped that the errors will prove to 
be few. For the living genera that have also been found fossil, the date 
and place of publication have been taken mainly from the Kew Index 
and have not in all cases been verified. The dates of these later genera 
are not, however, of great importance in the present connection, since 
botanists are not agreed as to the date that shall be taken as the initial 
point for genera. One school would make the introduction of binomial 
nomenclature, or the publication of Linnreus's Species Plantarum, 17513, 
as the initial point for both genera and species, while another school 
would take the publication of Linnseus's Systema, in 1735, as the start- 
ing point for genera. Other botanists would go still further back to 
Tournefort, who lias been called the father of genera, or even to the 
remote place in literature when a genus was first printed, no matter in 
what connection. It would seem wise, therefore, to settle on some 
important date as the initial point. For convenience the date selected 
in the Kew Index — 1735 — is here taken for the living genera. Fortu- 
nately the science of paleobotany is so young that all of the generic 
names that have been given iu it are of later date than any of the dates 
in controversy, since all are later than 1800. 
In the case of species, the original place and date of publication have 
been given in all instances. This is followed by several of the most 
important references, especially such as refer to descriptions and fig- 
i Ann. Kept. IT. S. Geol. and Geogr. Surv. Terr., pp. 307-309, 1871 [1872]. 
2 Op. fit,, pp. 410-417 (1872 [1873]). 
3 Op. cit.,pp.255 (1877 [1879]). 
4 Cret. and Tert. Fl., pp. 93-103 (1883). 
» Op. cit., pp. 115-120. 
6 Op. cit., pp. 206-212. 
7 Op. cit., pp. 266-272. 
"Monogr. U. S. Geol. Surv., XVII, pp. 222-225, 1891. 
9 Sixth Ann. Rept. U. S. Geol. Surv., pp. 443-514, 1888. 
