CRETACEOUS CONIFERALES 75 
of the more modern tribes of conifers have been published. It may 
be stated in general that the abundance of araucarineous or any other 
plant remains at earlier periods of the earth’s history does not neces- 
sarily supply evidence of superior antiquity. 
Whether the arguments advanced above for the derivation of 
the Araucarineae from a stock closely allied to the still flourishing 
but very ancient genus Pinus, be accepted or not, it is quite clear that 
a large part of the coniferous flora of the Cretaceous and probably 
earlier periods, was composed of types of araucarians, differing 
markedly in their wood structure, their wound reactions and general 
organization from the existing genera Agathis and Araucaria and 
their near relatives of the Mesozoic. 
In accordance with the facts thus far determined in regard to the 
structure of recent and fossil araucarineous woods, the Araucarineae 
may be separated in three sub-tribes as follows : 
ARAUCARIOPITYOIDEAE 
Wood tracheids with both araucarineous and abietineous pitting, 
the araucarineous pitting ordinarily confined to the ends of the tra- 
cheids. Traumatic resin canals resulting from injury often present. 
Medullary ray cells with abietineous pitting, :. e., with pits on the 
horizontal and terminal walls of, as well as on those in contact with, 
the tracheids. Leaves probably occurring on short shoots as in 
Pinus. Reproductive organs not accurately known (draucariopitys, 
Czekanowskia (?)). 
BRACHYPHYLLOIDEAE 
Wood tracheids with both araucarineous and abietineous pitting, 
the araucarineous pitting confined to the ends of the tracheids. 
Traumatic resin canals may be formed as the result of injury. 
Medullary ray cells with araucarineous pitting, i. e., the walls smooth 
except those in contact with the tracheids. Leaves not occurring on 
short shoots, various. Scales of the female cones various, peltate 
to squamiform, persistent or deciduous (Brachyphyllum, Geinitzia, 
Raritania, Widdringtonites, Thuites, Androvettia, etc.). 
ARAUCARIOIDEAE 
Wood tracheids with araucarineous pitting (radial bordered pits 
alternating or flattened by mutual contact). “Traumatic resin canals 
