[Marrmew] PALÆOZOIC ROCKS OF SOUTHERN NEW BRUNSWICK 87 
Arisaig section I have referred these basal beds to the Medina 
group." 
A section of these rocks is shown in the accompanying diagram 
and the contact of the Silurian with an older unconformable series is 
here well displayed. The older set of beds shows a core of massive 
gray quartzites, in a ridge covered on each side by masses of red vol- 
canic rocks? (grits and felsites); fragments of both members of this 
series, but especially of the quartzites, being common as boulders and 
pebbles in the overlying Silurian conglomerates. The section shows a 
blank in the middle where there is a gravelly beach; this beach is prob- 
ably underlain by dark gray shales, there being such beds at this horizon 
on the opposite side of the anticline of the older series. Thus it will be 
seen that these plant-beds are not quite at the base of the Silurian 
series but probably toward the top of Division 1. 
In illustration of the bearing of these plants on the Geological 
history of this district the writer has added a short section on the 
Physical aspect of the Silurian rocks in Charlotte and St. John counties (p. 
7); and another on the probable bearing of the structure and condition 
of growth of these plant remains, on questions of habitat and adapta- 
bility to conditions of growth (p. 11) so far as this may be gathered 
from their mode of occurrence; in brief, a discussion of the ecology of 
the world of plants of that early time. 
Description of the Species. 
The following is a description of the species of this flora that have 
been studied, and show sufficiently distinct generic characters. 
HIMANTOPHYTON® CASTORENSE gen. & sp. nov. 
Rhizomes apparently devoid of vascular tissue, probably composed 
of open, cellular, perishable tissue of unknown structure. . The surface 
in some examples has contiguous, shallow oval depressions, but no 
stigmata have been observed in these depressions. 
Leaves long, narrow, strap-like as preserved in the shale, flexuous, 
in many instances somewhat narrowed at the base. Frequently the 

1 Mr. W. H. Twenhofel of the Yale scientific staff has lately made a very careful 
survey of the Arisaig section and has submitted his fossils to Prof. Chas. Schuchert, 
who found nothing to indicate Medina; Mr. Twenhofel consequently refers all these 
lower beds to the Clinton group. 
2 Only one side of the anticline is shown in this section. 
3 imantos, a strap. 
