54 Prof. T. G. Bonney—Rounding of Alpine Pebbles. 
have only simple laminz, whereas Hozoon has connected or reticu- 
latory lamine. : 
2. Laminated passage-rocks have no structure other than crystalline. 
Eozoon has beautiful tubulation in its calcareous walls, besides large 
tubes or oscula. 
3. Sometimes (not usually) pyroxene is the siliceous part of 
Eozoon; or, as we hold, the mineralizing agent. More usually it is 
serpentine, sometimes loganite, or dolomite, or mere earthy lime- 
stone. It is not possible that all these minerals should assume the 
same forms. 
4, Pyroxene and serpentine both occur in nodules and bands in 
the Laurentian limestones, and in most cases without any traces of 
Eozoon, while Eozoon occurs in the limestone remote from such 
nodules and bands, where no passage of any kind can occur, and 
presents distinct forms. 
d. There are only two localities known to me, one in a quarry 
near Cote St. Pierre, and one at Burgess, where a bed with badly- 
preserved Hozoon occurs in a manner which would not even suggest 
an idea. Pyroxene is present in the one case, and loganite in 
the other. 
6. I have often thought of this suggested explanation, and have 
compared Hozoon with all sorts of banded and passage-rocks taken 
from the Laurentian and other formations, but have seen no reason 
to adopt such a view for Eozoon. I may add that in the Peter- 
Redpath Museum at Montreal I have accumulated a very large 
number of laminated and passage-rocks and concretions for purposes 
of comparison. 
7. How on such an hypothesis can we explain the beds of lime- 
stone composed of or filled with fragments of Hozoon ? 
EXPLANATION OF PLATE IV. 
Fig. 1.—Small specimen of ZHozoén, separated from the matrix, and showing a 
turbinate form. Nat. size. Coll. Dawson. : 
Fie. 2.—Weathered specimen of Hozodn, showing a section through the middle, with 
two cylindrical, osculiform, vertical tubes. The modification of the lamine at 
the sides of the tubes is similar to that at the exterior. Nat. size. Coll. 
Dawson. 
IJ.—Opsrrvations on THE RounpING or PEBBLES BY ALPINE 
Rivers, with a Nore oN THEIR BEARING UPON THE ORIGIN OF 
THE Bunter ConGLOMERATE.! 
By Pror. T. G. Bonnzy, D.Se., LL.D., F.R.S., F.G.S. 
HEN preparing my address to Section C in 1886, I had much 
need of information as to the amount of rounding which takes 
place in rock fragments when transported by rapid streams. Useful 
information and references are given in Dr. A. Geikie’s Text Book? 
and in De Lapparent’s “ Traité de Géologie,” * and there are the ex- 
1 A Paper read at the Meeting of the Brit. Assoc. (Section C) in Manchester, 1887. 
2 Book iii. pt. ii. sec, ii. 3 Book ii. sec. i. ch, ii. 
