176 Part II. Chapter r. 
Fagus, Liqudambar, Liriodendron, Magnolia, Sassafras, which are known 
from the Dakota formations (Upper Cretaceous). The following Dakota species 
of fossil plants may be compared with those of the present flera — 
Hedera ovalis Lesq. Hedera helix L. 
Laurus macrocarpa Lesa. Persea carolinensis Catesb. 
Liquidambar integrifolium. Liquidambar styraciflua L. 
Liriodendron sp. Liriodendron tulipifera L. 
Menispermites Menispermum canadense L. 
Platanus primaeva Lesa. Platanus occidentalis L. 
Rhus sp. Rhus metopium L. 
Sassafras sp. Sassafras officinale L. 
Some of the peculiarities of the past and present distribution of plants are 
made clear by a study of the coniferous vegetation of America. Many living 
conifers are extremely localized in their distribution, but before the glacial 
period many of them extended over a great portion of the northern hemis- 
phere. Zrbocedrus decurrens a tree restricted to California with a representative 
in Chili and in the South Sea islands occurred during Miocene times in Spitz- 
bergen with two species. — Seguoia gigantea which grows in .the Sierra 
Nevada Mountains of California occurred in Greenland in a related species S. 
Sternbergü. Sequoia sempervirens of the north California coast is related to 
S. Langsdorfii, which occurred in the arctic regions and eastern Asia. 
The majority of the very numerous North American conifers belong to 
separate sections of pines, as Pinaster, Taeda, Pseudo-Strobus, Cembra and to 
the genera Adies, Cupressus, Juniperus, Picea, Thuja and Tsuga. Of these, 
only a few are represented in Tertiary deposits, namely, remains of Adies and 
Thuja in Montana and Wyoming. More extensive remains of conifers occur 
in the north, for example in Banksland 74° 27' Abies Armstrongii and Picea 
Macclurii related to the modern Picea alba are found with a single species _ 
of Pinus; in Grinnell Land 81° 46° 7, axodium, Feildenia, Pinus and Pinus 
excelsa, while in Spitzbergen and Iceland occur remains of such genera 4$ 
Tsuga and Funiperus. 
The following List of Cretaceous and Tertiary plants of North 
A merica up to 1898 taken from KNOWLTON ’) will give a more adequate 
impression of the somewhat uniform flora which extended from the aretic 
regions through America far to the south. The number of recognized species 
in each case is given and genera only are mentioned about which there can 
be no doubt as to their identity. 
Abies I 
- Acer . 23 | Acorus 3 Aesculus R 
Abietites 11 Aceriphyllum 1 Acrostichopteris 5 Alnus 2 
ae 2 Acerates 1 erostichum 2 Amelanchier 4 
1) KnowLTon, F. H.: A Catalo 
gue of Cretaceous and Terti ts of North America 
Bulletin U. S. Geological Survey ertiary Plants o 
No. 152. Washington 1898. 
x 
