CALCITES OF NEW YORK 15 
16P2=(8.8.16.1) to existing forms becomes more apparent when the two 
principal series of pyramids are arranged in parallel columns thus: 
SP2=(1 123) 2P2=(1121) 
=P2=(2243) 4P2=(2241) 
=P2=(4483) SP2=(4481) 
*P2-(8.8.16.3) 16P2=(8.8.16.1) 
The prisms b(1010) and a(1120) are present, the former developed 
to a considerable habit. The crystals are terminated by the planes of the 
negative rhombohedron 6. (0112), and the scalenohedron K: (2131). 
Type III [fig. 3]. Crystals of type III occur in an association similar 
to that of type I with the important exception that in this case the thin 
layer intermediate between the crystallized calcite and the hmestone country 
rock is composed of marcasite. The crystals which average 7 millimeters 
in vertical length are rhombohedral-prismatic in habit, the dominant forms 
being the negative rhombohedron %.(0112) and the prism b(1010). The 
rhombohedral zone is comparatively rich in forms; the positive rhombo- 
hedrons p. (1011) m. (4041) and s.(13.0.13.1) are present, the two former 
as small but brilliant planes and the latter as a somewhat dull and rounded 
series of faces. The negative rhombohedron 7. (0445) is present in fair 
development, represented by planes of great brilliancy. Two positive 
scalenohedrons E: (5164) and K: (2131) in the zone [1011.1120] are present 
as bright series of planes striated parallel to the zone. 
Type IV [fig. 4, 5]. Crystals of this type occur associated with chal- 
copyrite, marcasite and some crystallized quartz in cavities in the lime- 
stone which constitutes the country rock. They are somewhat smaller 
than those of preceding types averaging 5 millimeters in vertical length. 
In habit they are scalenohedral, the negative scalenohedron g: (6.7.13.2), 
previously noted under the Antwerp occurrence, constituting the dominant 
form of the combination shown in figure 4. This combination is terminated 
