168 i Rhodora i [SEPTEMBER 
traumatic spaces in this lignite represent modified resin-canals. ‘They 
appear to be intermediate between typical traumatic canals and the 
wound-tissue of the modern Araucarineae, in which canals are never 
formed. 
One piece was observed which showed an apparent bit of wound- 
callus tissue, such as is formed in the wound cap of all the Conifers. 
We may now discuss the probable affinities of this interesting fossil. 
Its general anatomy places it unquestionably among the Conifers. 
One of the earliest scientific classifications of the woods of this group, 
but one which, in its main aspects, is largely adopted by most anato- 
mists of the present day, was put forward by Knavs (1). He divides 
coniferous woods into five main groups or "genera." The type 
Araucarioxylon comprises those forms in which the pits on the radial 
walls of the tracheids are closely adjacent and mutually flattened, and 
when occurring in more than one row, alternating with one another. 
The modern Araucarians represent this condition. All other conifer- 
ous woods, according to Kraus, possess circular, unflattened pits 
which, when in two rows, are opposite one another. The group 
Taxoxylon, with Taxus for its type, he separates on its possession 
of spirally thickened tracheids throughout. The genus Pityorylon 
includes all those forms in which resin-canals are present. ‘The 
remaining Conifers, which are considerably more simple in their struc- 
ture, are comprised under two groups — Cedroxylon, represented by 
such forms as Abies, Cedrus and Tsuga, in which resin-parenchyma is 
absent or nearly so; and Cupressoxylon (or Cupressinoxylon) in which 
occur the numerous forms of the Cupressineae and Taxodineae, where 
resin-parenchyma is abundant. 
According to the classification of Kraus, our fossil would clearly 
come under the head of Cedroxylon, for its pits are neither alternate 
nor noticeably flattened, its tracheids are not thickened spirally, and 
it possesses neither resin-canals nor resin-parenchyma in the normal 
wood. 
This classification, however, has recently been altered to some 
extent by GorHAN (2). Among other objections to the system of 
Knavs he remarks that as resin-parenchyma has been found rather 
abundantly in several of the forms commonly included under Cedroxy- 
lon, such as certain species of Abies, it does not form a good criterion 
for separating this type from Cupressinoxylon. He observes, how- 
ever, that the character of the wall of the ray-cell is quite distinctive 
