NOTICES OF BOOKS. 389 
Tuckerman, Epwarp, Esq.; Synopsis of the L1cHENS of the ` 
Northern United States and British America. 
This useful synopsis appears, indeed, in one of the volumes of 
the Proceedings of the American Academy of Arts and Sciences, 
but it was prepared for Dr. Asa Gray’s work, noticed in the pre- 
ceding article, “enlarged by the addition of many species from 
Arctic America and from the Pacific coast ;" the latter, we pre- 
sume, almost entirely, if not wholly, derived from the collections of 
our British Arctic travellers and voyagers, and of Messrs. Douglas 
and Scouler, though this is not very distinctly acknowledged. 
What Mr. Sullivant is in America among the Mosses and Hepa- 
tice, and what the late Dr. Schweinitz was among the Fungi, 
Mr. Tuckerman is among the Zichens. And this distribution of 
labour is of inestimable advantage to the promotion of science. 
The system here adopted is that of Fries, in his Lichenographia 
Europea reformata, with some emendations, derived from his 
later works. The characters of the sectious and genera in the 
Lichenographia have been throughout the basis of those now 
given, and in part are adopted entire. The N. American Lichens 
are here grouped into twenty-nine genera. A great number of 
the species, as we had anticipated, are the same as those of Europe. 
Genera Fiore AmericÆ Boreali-orientalis illustrata. The genera 
of the Plants of the United States, illustrated by figures and 
analyses from nature, by Isaac SenAGUE; superintended, and 
with descriptions, $c, by Asa Gray, M.D., &c., &c. vol. i. 
plates 1-100. Royal 8vo. Boston, 1848. 
The progress of art and science in the United States of 
America is, perhaps, nowhere better exemplified than in the 
volume now before us, which, if carried to completion, will, we 
hesitate not to say, rank among the most valuable and useful works 
that have appeared in any country. The “ Genera Plantarum Flore 
Germanicæ iconibus et descriptionibus illustrata,” of Théod. 
