25 
planation of the phenomena presented in such specimens 
as these. 
He also remarked that, so far as he had seen, this re-solu- 
tion of the surface of apatite crystals, which is common, and 
almost universal, in specimens from the Eozoic regions of 
northern New York, is not found in those from the crystal- 
line belt that flanks the sea-coast region, from the vicinity of 
New York City southward. In some cases, Pennsylvania 
apatites exhibit a surface with longitudinal striation, very 
different from the aspect of the northern New York crystals. 
He had not enough material to make a generalization of this 
kind, but called attention to it, as an interesting point for 
inquiry. 
Dr. B. N. Martin showed specimens of stibnite (with 
cervantite) from Battle Mountain, Nevada, where it is re- 
ported as occurring in large quantities. The metallic anti- 
mony, reduced from the sulphide, was also exhibited. 
THE PRESIDENT made some remarks reviewing the history 
of the class of fishes, as traced in the older rocks of North 
America. The earliest appearance of fishes would seem to 
be a point not capable of precise determination. The first 
definite traces of the group found in American rocks are, up 
to the present time, clearly in the Devonian age; but in 
Europe, the existence of quite anumber of genera and species 
inthe Upper Silurian period, is well established. In regard 
to the presence of fishes in the Lower Silurian seas, the case 
is very doubtful. Prof: Pander, many years since, announced 
the discovery in Russia, in rocks of Lower Silurian age, of 
small and peculiar tooth-like organs, which he regarded as 
the teeth of fishes, and designated as Conodonts. The opinion 
of Pander has not found general acceptance, however, and 
these bodies have been regarded by different writers as the 
teeth of gasteropodous mollusca, the spines of crustaceans, 
&c. It is perhaps, not impossible, nevertheless, that they 
may yet prove to be dermal ossicles of a tribe of small 
cartilaginous fishes. 
