CALCITES OF NEW YORK 93 
A variation of the type differing somewhat from the combination 
shown in figure 1 appears on extremely minute crystals which constitute 
a druse lining the walls of a thin seam on one specimen. These crystals, 
which average .5 millimeter in diameter are shown in figure 2. They are 
distinctly rhombohedral in habit, the prism a(1120) is reduced to a series 
of narrow planes and the prism b(1010) is entirely ‘lacking. The new 
‘scalenohedron r: (29.19.48.10) is considerably more prominent than in 
the former combination. A negative scalenohedron, the planes of which 
bevel the acute polar edges of (29.19.48.10) and which lies nearly but not 
quite in zone with the planes of the latter form,-gave measurements which 
corresponded to p: (1341). This relation adds weight to the contention 
that the positive scalenohedron in question differs slightly in position from 
R5. which latter form would lie exactly in the above zone. The letter r: 
has been assigned to this form. 
Type II [fig. 3]. Crystals of this type appear on one specimen fur- 
nished by Mr Hindshaw. They form a close aggregate deposited on a thin 
layer of pyrite and average 13 millimeters in diameter. The crystal units 
are apparently compound parallel groupings which take the general form 
shown in figure 3. This type is rhombohedral in habit, the prevailing 
rhombohedron being 4. (0112). The middle edges of this rhombohedron 
are replaced by the faces of the negative scalenohedron e: (9.11.20.4) and 
‘the prism a (1120) and the lateral solid angles by the prism b(1010). The 
faces of the rhombohedron in many instances are entirely composed of 
minute steep scalenohedral crystals having e: for the dominant form, and 
clearly marking the compound character of the crystal units. Drusy 
surfaces of the specimen furnished minute single individuals showing the 
scalenohedral habit illustrated in figure 3a. 
Type III [fig. 4]. Crystals of this type were noted on a single specimen 
collected by the writer in 1906. They occur in thick aggregates deposited 
directly on the syenitic gneiss of the country rock. The crystals average 
3 millimeters in vertical length and in many instances are doubly terminated. 
In habit they are scalenohedral, the dominant form being the positive 
