a as 
NOTICES OF BOOKS. 159 
species are given. The English names of the genera are perhaps ca- 
pable of improvement; and it may be worth the author's consideration 
whether, when a new edition is called for, as we trust will be the case 
ere long, it may not be right to make the English name of equal import 
with the Zatim one. We find “ Fork-moss," for example, to include 
the genera Aretoa, Cynodontium, Dicranum, Leucobryum, and Fissidens, 
which latter is placed widely apart from the preceding genera, in quite 
a different suborder. It is true, in olden time these all merged into 
one genus, Dicranum, or * Fork-moss." But there is as much need to 
change the English as the Latin names, if they are to be of any use. 
If this were done, the following singular misapplication would be 
avoided :— Polytrichum is very appropriately translated ** Hair-moss,” 
and the derivation given, ** modus, many, and Opi, hair; from the hairy 
calyptra.” P. undulatum is now separated from Polytrichum, and one 
of its characteristics is to have the “calyptra naked and smooth,” and 
hence its genus is named “ Aérichum,” from a and Opi, without hairs : 
but the English genus is still * Hair-moss." Probably Mr. Wilson 
was led to adopt this plan out of respect to the nomenclature of Sir 
James Smith (and no author was ever more happy in this department 
of botany) ; but such would not have been the wishes of Sir James 
himself. At the time he considered (with Linnzeus) Fissidens to be 
the same as Hypnum he gave it a corresponding English name; when 
, X was, with more propriety, referred to Dicranum, he called it *Fork- — 
moss;”’ and if he had afterwards ranked it in Fissidens, he would as- 
suredly again have changed the English name. s 
Gray, Dr. Asa: Puantw Nov THURBERIAN® ; the characters of = 
some New Genera and Species of Plants in a Collection made by George _ 
Thurber, Esq., of the late Mexican Boundary Commission, chiefly in 
New Mexico and Sonora. (Memoirs of the American Academy of- 
Arts and Sciences, N. S. vol. v.) Cambridge, Massachusetts. 4to. 
1854. peer 
We have here, from the untiring pen of our able and excellent friend 
Dr. Asa Gray, besides descriptions of new species of known, several 
new, genera; for example, Thurberia among Malvacee ; Holacantha : 
(Siniarubacee) ; Olneya (Leguminose) ; Petalonga (Loasacea) ; and Ere- — 
meastrum and Bartlettia (Composite). A vast number of observations —. 
