164 Prof. Don’s Descriptions of two new Genera of the 
hold an intermediate station between them. Their indefinite thecæ, varying 
from 3 to 20, and their naked buds, will distinguish them from Abietinee, 
while their fewer ovula, deciduous pericarpia, and strobiliform female spike 
will separate them from Cupressineæ. The species of Araucaria naturally 
separate themselves into two groups, characterized by peculiarities of habit 
and structure, as well as by their geographical distribution. The three Poly- 
nesian species having four cotyledons, and presenting a difference in the posi- 
tion of the leaves in the young and adult plants, have also fewer thecæ, and 
the crests of the anthers are short and closely imbricated ; while the two 
South American species present no difference in the position of the leaves in 
the immature and adult plants; the crests of the anthers are elongated and 
squarrose, and the thecæ double the number. The Chilian Araucaria imbri- 
cata extends along the Cordilleras of the Andes from the 35? to about the 
50° of S. latitude, while the Brazilian species occurs in the provinces of Rio 
de Janeiro and Minas Geraes between the 15? and 25? of S. latitude. The 
Araucaria excelsa appears to be exclusively confined to Norfolk Island, and 
the Cunninghamii to the east coast of New Holland, between the 14? and 
30° of S. latitude; the other species (4. Cookii, Br.) is limited to New Cale- 
donia and some small islands adjacent; and it is not improbable that the 
interior of New Guinea or Borneo may afford a fourth species of the same 
group, which, if it does not possess characters sufficiently important to rank 
as a distinct genus, it at least constitutes a very marked section, for which 
Salisburys name of Eutassa may be retained. The Polynesian species are 
remarkable for having the vessels of their fibrous tissue furnished on the sides 
parallel to the medullary rays with two or three rows of closely approximated 
and alternating dots having a hexagonal outline ; nor am I aware whether this 
peculiarity extends to the South American species, and to the genera Cun- 
ninghamia and Dammara, a point which I hope soon to be able to ascertain *. - 
* Having recently had an opportunity of examining the wood of Araucaria imbricata and brasiliana, 
and also of Dammara orientalis, I am now enabled to set this question at rest. The vessels composing 
their fibrous tissue present the same structure, having one or two rows of closely approximated dots 
with usually an angular outline, which, however, is not so regulariy hexagonal as in Araucaria ezcelsa 
and Cunninghamii, from the circumstance of the dots being often in a single series, but when they hap- 
pen to be arranged in two rows they are always alternate. "The vessels of Cunninghamia sinensis have 
the dots in single rows, with a circular outline, but they are smaller and more numerous than in Pinus. 
