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is overlaid by one of the important bituminous coal-seams of 
the Lower Coal Measures, known in Ohio as the “ Big Vein,” 
No. 6 of the survey, corresponding to the “ Upper Freeport 
Coal” of Pennsylvania. The record is a plain one; the lagoon 
that had formed the cannel finally “ grew up” with the marshy 
vegetation of its shores, as so many modern lakes are filling 
up with peat; the cannel deposit then ceased, and an 
ordinary coal-seam was formed in its place. 
Pror. T. EGLesron presented an account of the “ Systems 
of Notation of Crystals.” 
The whole subject of crystallography had, in his judgment, 
been surrounded with a great deal of mystery and supposed 
difficulty, which does not really belong to it. In this paper 
he reviewed the general principles which must enter into the 
study of crystalline forms, and of the notation of faces; and 
then traced the several methods adopted by the leaders of 
crystallographic science, and the successive simplifications 
which have been developed in notation. 
Crystallography must now be regarded as a German 
science ; for although begun by French students, it has been 
so much advanced and improved during recent years, in 
Germany, that the latter nation must be credited with its 
highest development. Hauy, although the father of this 
science, had yet some important errors and misconceptions. 
Founding his systems on prisms rather than octahedra, he 
could not reach the best modes of notation; and his idea of 
the rhombohedron as equiaxial triclinic, was wholly errone- 
ous, and prevented his ever understanding the real nature of 
the form, or of its many derivatives. 
Prof. Egleston illustrated his paper by blackboard drawings 
and models, the latter representing seven systems of crystal- 
line forms, as now recognized, three orthometric, three 
clinometric, and the hexagonal, with its four axes, standing 
alone as the seventh. The second clinometric system, the 
Diclinic, has not been generally recognized, and is not in- 
cluded in Prof. Dana’s enumeration. Its characters, however, 
are perfectly distinct, having the two transverse axes at right- 
