220 



NEW YORK STATE MUSEUM 



bined with the combination of the later generation and attain a size 

 of 5 centimeters on edge. They have in these instances a markedly 

 cubic aspect. Figure 3 shows the rhombohedron of this phase. 

 The compound crystals which were noted on one specimen of the 



Fig. 3 Fig- 4 



series available, consist of the rhombohedral element noted above, 

 upon the polar angles of which are superposed in parallel position 

 the scalenohedral combination shown in figure 4. The compound 

 crystals average 10 millimeters in vertical length. On the scaleno- 

 hedral elements, which represent the later generation of calcite 

 deposition, the following forms were observed: a (7180), <S. 

 (01T2), w: (3J45)> K: (2131), p: (1341). b: (3584) and X: 

 (4.16.20.3). The new dihexagonal prism — 00 R - = (7180") 



is represented by brilliant, well developed planes which gave good 

 reflections of the goniometer signal and lay well in the vertical 

 zone. The following zones were also observed : 



[1780: 1702:31^:3584: 1341^4.16.20.3: 1780] 

 [4311:3121:2131: I 341] 

 [7705:4135:3145:0775] 

 [2131:3584:0775:3211] 



Calcite crystals of negative scalenohedral habit were noted on 

 one specimen which yielded measurements approximating those for 



the scalenohedron — ^ R - _ (22.55.77.36) described by vom 



Rath from Bergen Hill. 1 The measured angles obtained from the 



1 vom Rath, G. Der Kalkspath von Bergen Hill, N. .f Zeit. f. Kryst. 

 1877. 2 '604. 



