CALCITES OF NEW YORK 71 
Scalenohedrons. The planes of 3: (6281) of the crystal of type III 
mentioned above are etched with several relatively large pits of the form 
and orientation shown at f. These are unsymmetric in outline and show a 
close resemblance to the etch pits noted on the plane f: (39.15.54.8) of the 
same crystal which are shown at g, figure 5. Considering these two forms 
of etch pits to be bounded by the same planes, it would seem possible that 
they are identical with the planes of p.(1011), 9: (2461) and 8: (4.6.10.1). 
It is to be regretted that the bounding planes of these etch figures were 
too small to admit of angular measurement with the instruments available. 
The etch pits figured at h and j show a different outline and orientation 
from the g outlines; they are undoubtedly bounded by the same planes as 
is also the composite pit occurring on the edge of intersection of the planes 
39.15.54.8 and 15.39.54.8. 
ANTWERP, JEFFERSON CO. 
Plate 6, figures 1-6 
The calcite crystals included under this occurrence were obtained from 
the Sterling iron mine about 2 miles north of Antwerp. They are asso- 
ciated with hematite, dolomite and ankerite, as well as with minute crystals 
of chalcopyrite and more rarely millerite. 
The crystals which are universally rhombohedral in habit, show three 
types corresponding to the calcite of three generations. Of these the posi- 
tive rhombohedral habit shown in figure 1 represents the earliest generation 
which preceded the genetic stage marked by the formation of ankerite and 
dolomite. An interesting demonstration of this sequence was noted: in 
the case of one specimen which showed several hollow spaces bounded by 
incrusting dolomite which correspond in outline to the positive rhombo- 
hedron p.(1011) and were evidently the result of the resolution of calcite 
of that habit. The layer of dolomite supported several calcite crystals of 
low rhombohedral habit, type II, having the negative rhombohedron 
6.(1012) for the dominant form. 
Type I [fig. 1]. The positive rhombohedral habit characteristic of 
crystals of the first generation was noted on two specimens and is shown in 
