32 
also the Buthrotrephis gracilis, and the Rusophycus bilobatus. 
The latter has sometimes been said to be merely the cast of a 
King Crab impression, but it is doubtless a plant and the most 
abundant fossil of the group in our vicinity. 
The Niagara formation contains a branching fucoid, while 
the beds of oolyte so closely resembling the roe of fish were no 
doubt formed by the cells of Glocotheca and Gloeocapsa in much 
the same manner that they form in Great Salt Lake and other 
places to-day. The Blue-green algae require carbon, which they 
abstract from the water, thus reducing its solvent power and 
causing it to deposit masses of the cells which form the beds on 
the bottom of water. 
The lignilites of the Salina group are of mineral rather 
than vegetable origin, although in the flints of the Corniferous 
we find some protophytes, diatoms, and desmids, also imperfect 
land plants belonging to the class of Lepidodendrids. 
The so-called coal of the Marcellus group is of vegetable 
origin, although the terrestial plant life at this time was quite 
limited, and the search for coal in paying quantities in this for- 
mation must ever prove futile. In the Hamilton period such life 
was more or less abundant as is proven by the lepidodendrids 
occasionally found at Pratt’s Falls and other places, the trunk of 
a tree fern unearthed near Cazenovia, and the somewhat doubt- 
ful forms from Skaneateles Lake region which have been re- 
ferred to the sigillaria and archeocalamites. 
It is also of interest to note that our shells and petrified trees 
are occasionally pierced by a boring algae, belonging to the class 
of Schizomycetes, proving the existence of bacteria even at that 
early time. 
The second paper of the evening entitled: 
VARIATIONS IN TRILLIUMS, 
was read by Mrs. L. Leonora Goodrich. 
The paper was illustrated with a large number of specimens 
which had recently been returned to Mrs. Goodrich from the 
Philadelphia Academy where they had been sent for description. 
