FOSSIL CONIFEROUS WOOD. 167 
Fosstz Contrerous Woov.—The coniferous wood of the 
secondary formations of England, belongs for the most part 
to the Araucarian type: that is, the glands, when in 
double rows, are placed alternately, as in the Norfolk Island 
Pines (Wond. p. 696), and not side by side, as in the 
common European species of firs and pines (Bd. p. 486). 
Numerous sections of this kind of fossil wood are figured by 
Mr. Witham, from specimens obtained from Lennel Braes, 
on the banks of the Tweed, near Coldstream; and from 
near Allanbank Mill, in Berwickshire (Obs. Foss. Veg. p. 14) ; 
a fossil trunk, 40 feet long, discovered in Craigleith Quarry, 
near Edinburgh, at a depth of 136 feet, possessed the same 
structure. 
PALHOXYLON (coniferous wood of the Coal Measures).— 
The existence of coniferous trees in the Carboniferous flora, 
and the fact that their trunks and branches had contributed 
to the formation of coal, was first discovered and clearly 
demonstrated by Mr. Witham in the work to which reference 
has been made. Figures of the peculiar structure observable 
in thin slices of coal, are given in Obs. oss. Veg. pl. iii. iv. v. 
This carbonized wood resembles that of the Araucariz in 
the multiple series of ducts, and their alternate arrangement ; 
but the presence of thick compound medullary rays in these 
stems,—a character unknown in any living conifers,—led 
M. Brongniart to place them in a separate genus—Pale- 
oxylon (ancient wood) ; characterized by the presence of 
medullary rays formed of numerous layers of cells, which 
are not arranged in superimposed series, and that present 
a lanceolate or oval form, in a section perpendicular to their 
direction.* 
* The Pinites Withami, and P. medullaris, of Lindley and Hutton, 
figured in Mr. Witham’s work, belong to this genus. It may interest 
the reader to know that slices of these woods prepared for the micro- 
scope by Mr. Nicol, (presented to me by the late Dr. Henry, of 
Manchester,) not only expose the vegetable organization in an 
