THE HAMILTON ASSOCIATION. 75 
in this unusual manner. They are probably confined to two layers 
in the Barton shales, at least they have not yet been found in any 
others. As in Inocaulis plumulosa (Hall) the rain-like process, 
frequently noticed, may represent the cellules of a graptolite. A 
few rather doubtfully appeared to look on it as representing a Marine 
Annelid. They vary in length, viz., from one to three inches, 
being flattened in the indurated Niagara shale. The body, or axis, 
now seems broader than in the natural state before it became fossil- 
ized, and indeed it does occasionally assume a worm-like appear- 
ance. I was of this opinion for some time, but such forms offer 
little for preservation in a fossil state. We know the chitonous 
teeth may be, and have been, preserved in Silurian beds (I think in 
Cambro-Sil. rocks also), but even comparatively recent ones display 
no instance where the softer part of an Annelid has been recognized 
in a fossil state. There are no burrows or trails. 
While I am satisfied Dr. Spencer has correctly assigned it to 
the Hydrozoa, it may be questioned as to what particular group 
it comes under. I feel inclined to imagine it to be the representa- 
tive of an entirely new genera. It appears to differ almost as much 
from the Quebec Phyllograptus as from the Niagara Inocaulis. 
Another minute graptolite puts in an appearance in Barton 
shale, a little below near the Lime Kiln. It seems to be very rare. 
We may not, as yet, have hit off its headquarters, or specific centre. 
A. few fine slabs of shale, with the two characteristic Barton Fucoids, 
were also obtained. They usually display rounded branches on the 
surface of the flags ; they are never found in the same layer, always 
separately ; one is much slighter than the other ; both belong to the 
same family group. Perhaps the most interesting find was in the 
banks of the stream lower down. The fossil bears a marked 
resemblance to the curved fin-spine of a species of shark. Such 
phosphatic spines are not uncommon in the chert and limestone 
beds of the Niagaras near the city ; some, probably, were tail spines 
of a Crustacean, viz., Ceratiocaris or Colpocaris. Others are so 
large and heavy, apparently, that it is difficult to see how an ordinary 
member of the Crustacea could move freely about with such a 
weight attached. Hugh Miller, in one of his works, stated that the 
defensive spine of an Onchus had been detached in limestone of the 
lower Silurian, or Cambrian Age. But the one he referred to was 
