: single species, and the death of both isolated species and i 
100 REVIEWS AND BOOK NOTICES. 
Comparing the Devonian flora with that of the Carbonifi 
period, so familiar to most of our readers, who have seen t 
beautiful impression of fern leaves from the shales enclosing 
of coal, our author states that generically the two floras arei 
main identical. ‘‘The most important and characteristic ¢ 
boniferous genera are also among those best represented in t 
older flora. On the other hand, while some Carboniferous g 
have not yet been recognized in the Devonian, the latter po 
ses some peculiar generic forms of its own, and these are 
cially abundant in the lower part of the system. As examples 
such genera I may name Psilophyton, Prototaxites, Leptophle 
and Arthrostigma. Further, it may be remarked that these 
culiar Erian plants present highly composite or synthetic types 
structure, giving to these a more archaic air than that of the C 
boniferous flora.” ‘Specifically, however, the Devonian flora 
almost altogether distinct from the Carboniferous. Ee be: Sal 
lar local conditions which prevailed so extensively in the Ca 
iferous period. . The Devonian plants probably grew On 
rocky islands, bordered by much less extensive and perm 
lowlands than those of the Carboniferous era.” 
of his patient and extended researches in fossil botany. 
the origin of the flora as a whole, as well as 
floras, inevitably arise and must be met by the student in $€ 
They are discussed by our author in his usual candid and 
osophical spirit. He refers— 
“For a moment to views of the sequence of Pals«oz° a 
which poge be entertained in accordance with theories is 
vation of species now prevalent. The lower Devonian’ 
