88 THE ROYAL SOCIETY OF CANADA 
base of the leaf has a shoulder, or rounded wing, on each side, and ter- 
minates in a narrow, strongly vascular extension or tang, that possibly 
was buried in the substance of the rhizome, but was torn out when the 
leaf was detached. Above the base of the leaf there is often a narrow 
median groove extending 12-24 cm. from the base, and fading out on 
the blade of the leaf. Also there is usually visible in the proximal part 
of the leaf, a strong vascular band, sometimes forking near the base 
and extending up the middle of the leaf, or deviating to the border, 
traceable for 24-48 em., and often much further up the leaf. This band 
in its upward course may (as preserved in the shale) curve from side to 
side of the leaf. The upper part of the leaf is smooth and devoid of veins 
or ribs, and the leaves have a faintly granulate, smooth, shining surface. 
The leaves have been traced for a length of five inches and are of nearly 
uniform width throughout; the width is usually about 6 em. though 
occasionally leaves of twice this width have been seen, but these fork 
near the base. Young leaves of 2-3 em. are occasionally found, thinner 
than the adult leaves, and shorter, some being only 50-100 em. in length; 
they are bluntly pointed at the tips; but parts of adult leaves which are 
thought to be terminal have bluntly rounded ends. The leaves seem to 
have been attached to subterranean or procumbent rhizomes, and no 
erect stems have been observed. 
The Fruiting stem is erect, from six inches (to a foot?) in length, 
much branched in the upper part, and finely divided at the extremity, 
into numerous short peduncles usually bare of bracts or fruit. In 
general the stem in its manner of branching resembles that of Psilo- 
phyton robustius Dn'. but with the lower branches less numerous, and 
having no pods. The fruiting stem is woody and has left a dense coaly 
band where it has been buried in the shale.’ 
Fruit.—No flowers are known, but the fruit has been preserved 
and consists of a minute seed which in some instances still remain at- 
tached to the peduncle. Usually the seeds are detached and are oval, 
from 4 mm. to $ mm. in length; they are minutely striate with a re- 
ticulate ruffling of the surface in which longitudinal striz predominate. 
Occasional groups, or scattered clusters of the seeds are found on the 
surfaces of the shales, where they have fallen from the stems, or they 

1 Fossil Plants of the U. Silvr. and Devon. format. Canada, Pl. XII, fig. 138. 
2“ Vernation.” The coiling of the tips of the fruiting branches of this plant 
(and perhaps also in Psilophyton) is not at all of the nature of vernation in Ferns; 
vernation in this Class is found in the tips of the young frond, and characterizes the 
vernal unfolding condition of the frond. The coiling in Himantophyton however, 
occurs in the mature branches of the fruiting stem, and the coil is very minute and 
slender. 
