Mineralogy and Geology. 401 
bead yellow while hot, bluish opalescent when cold. In 
sed tube yields acid water. 2 
With considerable difficulty 0°679 gram of the mineral, free from 
mixture, was obtained and submitted to anlysis with the follow- 
g percentage result : 
Water, 3°42 
Fluorine, “75 
ilica, 36°49 
Sesquioxyd of iron, 754 
eM aS ls 24°09 
a, 16°03 
Loss, 11°68 
100°00 
aes & 
of fine sees and measuring from half an inch to four inches 
s. A black blende, containing much iron, has been found in 
s period. Previous to that time large collections of fos- 
| been made from rocks of that age on the Atlantic and 
‘coasts, but the beds which furnished them were marine sedi- 
ian fish. In these remains there was found a generic cor 
ence with those of the middle and upper Cretaceous beds 
ad April 224, 1867, Annals of the Lyceum of Natural History in New 
‘You ix, April, 1868. ae 
Jour. Sc.—SEcosp SeRims, Vou. XLVI, No. 138.—Nov., 1868. 
