TRANSACTIONS OF SECTION K. 1025 
The block, from which several sections have been prepared, is a striking example 
of the preservation of the minute structure of a Coal Measure plant on a large 
scale; it consists of a mass of wood at least 6 cm. thick in a radial direction, and a 
pith about 3 cm. in diameter, but without any trace of cortical tissue. Sections 
obtained from this block, and included in the Williamson Collection, were described 
at some length in the recently published memoir by Williamson and Scott on 
Lyginodendron and Heterangium. The examination of additional specimens has 
led to a somewhat fuller diagnosis of the structure and a more detailed comparison 
with Lyginodendron Oldhamium and other plants. The main mass of the wood 
possesses a structure practically identical with that of Lyginodendron Oldhamium 
and recent cycadean stems; internal to the centrifugally developed secondary wood 
there is a fairly complete and narrow ring of centripetally developed xylem, In 
the pith there are numerous secretory canals and nests of dark-coloured sclerous 
cells. No definite traces of primary xylem like that of Lyginodendron Oldhamiuni 
have been detected. As a matter of convenience the specimen may be designated 
Lyginodendron robustum. 
5. A New Species of Albuca (A. prolifera, Wils.). By Dr. J. Wixson. 
6. Observations on Hybrid Albucas. By Dr. J. Witson. 
1896. 
