Notes. 
61 7 
The smaller circum-medullary strands, which clearly represent leaf- 
traces at a greater distance below their point of exit, also show mesarch 
structure, but in the smallest of them the protoxylem-group approaches 
the inner edge of the strand. It is evident that the outgoing leaf- 
trace became much enlarged on approaching its point of exit. The 
same thing is seen in Poroxylon , and in Lyginodendron Oldhamium , 
though less conspicuously. The arrangement of the larger outgoing 
traces agrees with a 2/5 phyllotaxis. The internodes were pre- 
sumably short, for in the Williamson specimen three bundles are 
seen passing out in one transverse section. The bundles soon 
assumed a nearly horizontal course, for they are sometimes cut almost 
transversely in tangential sections of the wood. 
The structure of the secondary wood is in all respects that of 
a typical Araucarioxylon\ the rays are narrow, usually uniseriate, 
occasionally two cells thick in the middle. In height they vary as 
a rule from one to about twelve cells, but a few are higher. The pits 
are limited to the radial walls of the tracheides ; they are ranged 
in three or four alternating rows, and have an hexagonal outline, with 
the slit-like pore often beautifully preserved. The medullary rays are 
of typically muriform structure. 
This stem thus combines the primary xylem-structure of the 
Lyginodendreae with the secondary wood of a typical A raucarioxylon. 
The name fasciculare is proposed for this form of stem on account of 
the extreme prominence of the primary bundles. 
The second species is from the same horizon as the first. 
Mr. Kidston’s sections, on which the following account is entirely 
based, bear the inscription: ‘ Araucarioxylon, Lennel Braes, Berwick- 
shire. Calciferous Sandstone Series, B. N. Peach, 1883/ 
This stem differs strikingly from the foregoing in the size of its 
pith, which is nearly an inch (22 millim.) in diameter. The pith 
itself is remarkable ; it consists of large, very short cells, with abundant 
‘ secretory sacs ' among them. There are horizontal lenticular gaps 
in the tissue, suggesting an approach to the discoid ‘ Sternbergia y 
structure so characteristic of the pith of Cordaites. 
The primary xylem-bundles in this case are small, ranging from 
• 15 to <3 millim. in diameter, but are very numerous. Forty-six 
were counted in a transverse section, but the number no doubt varies. 
They are ranged in an irregular ring round the periphery of the pith, 
in which most of them are imbedded, very few being in actual contact 
