
602 REVIEWS. 
A convenience in the arrangement of the book is the list of the (75) 
genera, placed under their ates suborders and phe, which is 
given at the beginning. The generic characters are given in as few 
words as is consistent with intelllethiity, and the species are described 
in much the same manner, all the words of frequent use being abbrevi- 
ated. The greater part of ee PR synonomy, which is often of a 
complicated character, is left o The species of Hymenophyllum and 
Trichomanes, which have been so pee multiplied by certain authors, are 
here reduced in the ratio of something like two hundred to five hundred. 
um e 
lamented Mettenius adopted, that they are exindusioid eee with 
which they agree in aspect and other characteristics, and where so many 
of them have been absorbed by the discovery of an indusium 
The inclusion of the suborders specially mentioned in the title is a 
great boon, for here we have them, for the first time, comprehensively 
described. — H. Mann. 
THE T AND FUTURE OF OUR PLANET.{—The author says, in his 
ngon ta he has freely used the writings of Lyell, Owen, Hail, 
hey had done the writings of others.” Now these are the 
nucleus of their own original investigations, whereas Mr. Denton has 
no such nucleus, the whole being a compilation. .As such, however, it 
a popular manner, the acaba which have been made in the geology 
three first appear simultaneously: ae he Protozoa are wholly ignored and 
although it is rather too soon to speculate about them, we think the 
whereas every sntudalien supposes that they must have had soft rudi- 
found in the Potsdam sandstone aa elsewher ad 
The explanation of the different ages of aad is very apt to misle 
ve reader into the belief, that the more modern granites have only been 
rmed in the centre, and spouted up in veins through the later rs 
asian it occurs-in masses just as the older granites occur, and not 
fering except in 
Th 
age. 
e illustrations are extremely pogr, but the lectures are popular, 


liain Past and Future of our Planet: By shasta Denton. Svo, pp. 34t.: Boston, 1868. 


