488 ORGANIZATION OF 1 OSSIL CONIFER^E. 
the four recent species of Araucaria at present 
known, one is found on the east coast of New 
Holland, another in Norfolk Island, a third in 
Brazil, and the fourth in Chili. (Foss. Flora, 
vol. ii. p. 21.) 
Whatever result may follow from future inves- 
tigations, our present information shows that the 
largest and most perfect fossil Coniferae, which 
have been as yet sufficiently examined from the 
Coal formation and the Lias, are referrible either 
to the genus Pinus, or Araucaria,* and that both 
these modifications of the existing Family of 
Coniferae date their commencement from that 
very ancient period, when the Carboniferous strata 
of the Transition formation were deposited. 
* Mr. Nicol states that in fossil woods from the Whitby Lias, 
when concentric layers are distinctly marked on their transverse 
section, (PI. 5G^y Fig. 2, a, a.) the longitudinal sections have 
also the structure of Pinus (PI. 50^, Fig. 1.); but when the trans- 
verse section exhibits no distinct annual layers, (PL 5^^, Fig. 
4.) or has them but slightly indicated, (PI. 56^, Fig. 6 a) the lon- 
gitudinal section has the characters of Araucaria. (PI. 50^^, Fig. 
3, 5.) So also those Coniferae of the great Coal formation of 
Edinburgh and Newcastle, which exhibit the structure of Arau- 
caria in their longitudinal section, have no distinct concentric 
layers ; whilst in the fossil Coniferae from the New Holland and 
Nova Scotia Coal field, both longitudinal and transverse sections 
agree with those of the recent tribe of Pinus. 
Mr. Witham also observes that the Coniferae of the Coal for- 
mation, and mountain limestone group, have few and slight 
appearances of the concentric lines, by which the annual layers 
of the wood are separated, which is also frequently the case with 
the Trees of our present tropical regions, and from this circum- 
stance conjectures that, at the epochs of these formations, the 
changes of season, as to temperature at least were not abrupt. 
