Dr. A. G. Nathorst—Siiurian “ Plants” of Wales. 33 
- T have now done my best with a difficult subject, and, if unable to 
absolutely clear it up, I trust that what has been said may at all 
events be a step towards that result. From the evidence before us 
it seems to me that our Red Chalk is probably one of two things: 
either it is a part of the Lower Chalk, or else it is a representative 
of that and of the upper part of the Gault. It is certainly Chalk 
to some extent. Consequently, were I obliged to confess my belief 
in any one formation, I should simply say that Red Chalk is—Red 
Chalk. 
VI.—On tHe So-catuep “ Puant Fosstns”’ FROM THE SILURIAN OF 
CrenTRAL WALES. 
By Dr. A. G. Narnorst, 
of the Geological Survey of Sweden, Stockholm. 
TN the Gronocicat Magazine, Dec. II. Vol. 1X. November, 1882, 
my esteemed friend, Mr. W. Keeping, describes (pp. 485-491) 
some markings from the Silurian beds of Central Wales, which he 
considers to be fossil plants. The description of those markings, 
however, so far from supporting the correctness of Mr. Keeping’s 
views, seem, on the* contrary, to put it quite beyond doubt that the 
objects referred to are only trails and burrows of Annelids. It is 
indeed most surprising that Mr. Keeping, although referring to my 
paper on trails of different animals, etc., seems to have taken no 
notice whatever of the statements which are there brought forward 
as to the mode of occurrence and structure of the worm trails. For 
if this had been done, I think that the objects referred to would 
never have been described as fossil plants. 
First, let us consider the branching, which, according to the 
views expressed by Mr. Keeping, should be per se sufficient to de- 
monstrate the plant-nature of the markings. Now this statement is 
indeed most surprising, since I long ago (in my work referred to) 
demonstrated not only that branched trails can be produced by 
worms, but also that there are some species of these animals the 
trails of which are always branched. The branching affords conse- 
quently per se, no proof whatever as to the plant-nature of the 
markings. Secondly, the regularity of the branching, shown in the 
figures 1 and 2 of Mr. Keeping’s paper, cannot be regarded as any 
support for the supposed plant-nature, as precisely the same alter- 
nating position of the branches is sometimes very conspicuous in the 
branched worm trails (vide plate 9, fig. 1, of my memoir). Further, 
it ought not to be forgotten that the worms referred to not only 
produce branched trails on the surface of the sediment, but also in 
the mud, and when such branched tunnels are filled with sediment 
or by mineral matter, they appear like cylindrical branched stems, a 
transverse section of which precisely ‘“‘ resembles rain pittings.” 
! Om spar af nagra evertebrerade djur m.m. och deras paleontologiska betydelse. 
With a French translation: Mémoire sur quelques traces d’animaux sans vertébres 
etc. et de leur portée paléontologique. (Svenska Vetenskaps Akademiens Hand- 
lingar Bd. 18, No. 7, Stockholm, 1881.) 
DECADE II.—VOL. X.—NO. I. 3) 
