CALCITES OF NEW YORK I1Q 
are considerably striated parallel to the zone axis, producing multiple 
images of the goniometer signal and rendering the measurement of the 
interfacial angles somewhat difficult. The forms are, however, sufficiently 
rational and well established to admit of no doubt as to their true indexes. 
Type III [fig. 5]. The crystals of this type which were noted only on 
the specimens from Alsen, are colorless, transparent and covered with a 
light, yellow, iridescent film probably due to iron. They are scalenohedral 
in habit, presenting three scalenohedrons of the zone [1102.1011.1120], 
viz: v:(7.4.11.15), G: (7295) and P: (3251) the last of which is also occa- 
sionally present on the crystals of type II from this locality. The negative 
rhombohedron 6. (0112), which is a dominant form on the crystals of types 
I and II, is here present in relatively small development. Small planes of 
the prism b (1010) are present on combinations of this type. As in the case 
of the crystals of type II the scalenohedral zone is much striated. 
SUMMARY OF MEASURED AND CALCULATED ANGLES 
LETTER ANGLE : NC: a | MEASURED ! CALCULATED 
READINGS 
| ° Vise ° , 
Dela LOM ez: le NS 5 fe Lie PS oy! 47 
pasGe 1011 : 7295 8 16 15 16 36 
joe ele 1011 2 SE 3 19 4) 19 25 
DeseN: 1011 : 5382 6 34 41 34 28 
NEESINE 5382 : 5832 3) Te, 49 UP 54 
pee: 1OTT = 3251 9 37 34 37 595 
bi) SND LORS See Ope 3 92 ys) 92 46 
uy ely HORS MIB: Qe ses. Oe a 2D) 3 25 5 
i) By fORseBe Zao LO aise? 6 39 24 39 13 
NM: : Me: We OSTA 2 Whe a 5 94 D4 94 56 
NN: : Mt: ThibeSxe IAL es Ta le 8 22 41 23 ii 
M:N: tie Oia i ate 40 3721 “40 36 
HUDSON, COLUMBIA CO. 
Plate 24, figure 6 
Small crystals of calcite occur in veins in the Becraft limestone of the 
Helderberg series at the Hudson City quarry sittated a mile southeast of 
Hudson. 
