REVIEWS. 
187 
AMERICAN SURVEY PUBLICATIONS. 
T HE most important work published by the United States Survey of tbe 
Territories that has appeared during* the present quarter is Professor 
Leo Lesquereux’s description of the “ Tertiary Flora * of the Western Terri- 
tories.” In this splendid volume, which is to be regarded as tbe comple- 
ment to his previous great work on the “ Cretaceous Flora ” of the same 
region, Professor Lesquereux describes nearly 330 species of plants which 
have been obtained from the great series of lignitiferous deposits spread 
over a vast portion of Western North America, extending certainly from 
New Mexico in the south to and beyond the northern boundary of the 
States. The true position of these lignitic beds was long a matter of dispute,, 
seeing that in their lowermost deposits certain fossil animals of Cretaceous 
type had been found. From the researches of the late Professor Meek “ On. 
the Invertebrate Cretaceous and Tertiary Fossils of the Upper Missouri 
Country” (see “Pop. Sci. Rev.,” N.S. Vol. I., p. 79) it seems clear that in 
these lowest beds, immediately succeeding the series known as the Fox Hills 
group, the highest undoubtedly Cretaceous series, we have traces of a transi- 
tion from Cretaceous to Tertiary conditions : but, considering the preponder- 
ance of the evidence from the fossil Flora, if a line is to be drawn between 
the two it must pass below the lignitic beds. It is in this sense, apparently, 
that Professor Lesquereux treats all the plants described in his present 
magnificent work as of Tertiary age. 
It will be unnecessary here to refer in detail to the species described, most 
of which are new, although a few are identical with, and many related to 
European and Greenlandic forms. We may mention, however, that the 
author notices four species of parasitic Fungi {Sphceria and Scleroiium) , and 
has also discovered traces of a Lichen which he refers to the genus Opegrapha. 
Four Lycopods are described, three of which belong to Selaginella ; the Ferns 
belong to Tertiary types ; and the total absence of Gleiclienia is interesting 
in connection with the question of the age of the deposits. Among the 
Pheenogams we find the usual Tertiary genera. 
By his researches Professor Lesquereux has determined the equivalence of 
the different deposits over a wide extent of country, and has also been led to 
recognize four groups in the Lignitic formation of the Upper Missouri and 
Colorado regions. 
The first or lowest group, from which, probably owing to its being most 
worked for fuel, 200 out of the 329 recorded species have been obtained, has 
only 16 species known to occur in higher Tertiary groups. Its flora includes 
nearly all the Ferns, Palms, Figs, Cinnamons, Magnolice , and Rhamnese of 
the Lignitic formation. It is referred by the author to the Lower Eocene. 
The second or Evanston group, from which only 34 species of plants are 
known, has 20 of these peculiar to itself. Its characteristic plants are five 
* “ Report of United States Geological Survey of the Territories.” F. V. 
Hayden, U.S. Geologist-in-Cliarge. Vol. VII. “ Contributions totheFossii 
Flora of the Western Territories.” Part II. “ The Tertiary Flora.” By Leo 
Lesquereux. 4to. Washington : Government Printing Office. 1878. 
