42 THE HAMILTON ASSOCIATION. 
(single valves generally), numerous Bryozoons, corals. The latter 
alone is sufficient to show the sponges must have flourished in com- 
paratively shallow water, since leading naturalists such as Milne, 
Edwards, Sars and E. Forbes concluded that the coralline zone was 
from 5 to 50 fathoms, and the deep sea coral from 50 to too, ora 
little more. We may be reminded of the extraordinary depth 
reached in recent scientific borings in reefs off the coast of 
Australia, but that merely indicates slow submergence. 
The reef-building Polypes, Porites, Meandrina, Madripora and 
Astrea are confined to limited depths, according to Quoy and 
Gannard. We may conclude, remarks Darwin, that in ordinary 
cases reef-building Polypifers do not flourish at greater depths than 
20 or 30 fathoms. 
The plants of the chert beds are poorly preserved and few in 
number, but they indicate a litoral (perhaps a laminarian zone), viz., 
from low water to 15 fathoms. Yet here their representatives can 
hardly admit of denial, since their production is easily accessible to 
any one who doubts their occurrence. The writer must admit that 
he has merely obtained impressions of single (scattered) valves of the 
Lamellibranchiates, save in one or two very rare instances, which 
scarcely admits of positive assertion at the present time. 
NOTES. 
Mr. Schuler had on exhibition one very fine specimen of 
Graptolite’ Dittyonema, showing the stem and root; also Cantho- 
graptus (new variety), and a new variety of sponge. 
Col. Grant showed several new varieties of /zocaulis from the 
Niagara formation ; Rhcnopora Tuberculosa, Fucoid from the blue 
building bed, Niagara formation ; a number of specimens of Sponges, 
Astylospongia, variety ; a large collection of fossils from the Hudson 
river formation, and three Ovthoceras of different varieties. 
A letter was received from Mr. Ray Lankester, Director of the 
British Museum of Natural History, acknowledging the receipt of 
Silurian fossils from Niagara formation of Hamilton ; from John M. 
Clarke, State Palzeontologist, New York State Museum, acknowledg- 
ing the receipt of information about the rock system near Hamilton ; 
from W. A. Parkes, acknowledging the receipt of several specimens 
received by him on his visit to Hamilton; from J. F. Whiteaves, 
acknowledging package of fossils from the Niagara chert and drift 
shingle of Winona. 
