226 Canadian Record of Science. 
(11.) Alternation of Mineral Layers. 
It has been suggested by Mr. Julien* and others that 
Kozoénal structure may be due to the alternation of mineral 
layers formed in the passage-beds between concretions and 
other mineral masses, and their enclosing matrix. The 
objections to this view are: 
1. Laminated passage-rocks and laminated concretionary 
forms have only simple laminz, whereas Hozoon has con- 
nected or reticulating lamine. 
2. Laminated passage-rocks have no structure other than 
crystalline. Hozoon has beautiful tubulation in its calcareous 
walls, besides large tubes or oscula. 
3. Sometimes (not usually) pyroxene is the siliceous 
part of Zozoon; or,as we hold, the mineralizing agent. 
More usually it is serpentine, sometimes loganite,or dolomite, 
or mere earthy limestone. 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 Hozoon, while Hozoon occurs in the 
limestone remote from such nodules and bands, where no 
passage of any kind can occur, and presents distinct forms. 
5. 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 even suggest such 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 Hozoon. I 
have accumulated in the Peter Redpath Museum at Montreal 
as above stated, 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 limestone composed of or filled with fragments of 
Hozoon ? 
* Proceed. Amer. Assoc. vol. xxxili. 1884, pp. 415, 416. 
