In the Araucarian type of wood (Araucaria and Agathis) the bordered pits, which occur in two or three rows on the radial walls of the tracheids, are in mutual contact and polygonal in shape, the pits of the different rows are alternate and not on the same level; in this type of wood the annual rings are often much less distinct than in Cupressus, Pinus and other genera.
C. Jeffrey have recently shown that some Lower Cretaceous specimens of the well-known genus Brachyphyllum obtained from Staten Island, N.Y., possess wood of the Araucarian type.
Some of the fossils referred to the genus Kaidocarpon, and originally described as monocotyledonous inflorescences, are undoubted Araucarian cones; other cones of the same type have been placed in the genus Cycadeostrobus and referred to Cycads.
Hudlestoni, and named by Carruthers Kaidocarpon ooliticum, afford good illustrations of British Araucarian flowers.
The well-known Whitby jet of Upper Liassic age appears to have been formed to a large extent from Araucarian wood.