146 TRANSACTIONS OF THE [FEB. 19 
Discussion by Prof. Kemp. Tin ores have been known for 
some years as occurring in Llano Co., and in the Trans-Pecos 
region, Texas (Texas Geol. Surv. Second Ann. Rep., p. 595, 690 
and 713). It is interesting to have their invariable associate, 
topaz, also brought to light. 
On Some New Forms of Wollastonite from New York 
State. 
By Herneicu Ries. 
The specimens described in this paper were obtained six miles 
from Harrisville, N. Y., along the stage road to Fine, on the 
land of H. Johnson. The wollastonite is said not to be abun- 
dant at this locality. Some of the crystals are of large size, and 
all are more or less weathered, so that a hand goniometer had to 
be used in measuring the angles, but the readings were sufli- 
ciently close to determine the different faces with certainty. 
A noteworthy feature of all the specimens examined is the 
presence of grains or lumps of unaltered green pyroxene scat- 
tered through them. This, together with the fact that many of 
the crystals examined resembled those of the Pitcairn pyroxene 
in form, led to the opinion at first that the specimens might be 
altered pyroxene. Measurements of the various angles, how- 
ever, soon dispelled this idea. The grains and lumps of py- 
roxene, so far as observed, always occur near the surface of the 
wollastonite crystals, and wherever the former showed recog- 
nizable faces it was found to be simply an intergrowth and not 
a parallel growth of the two minerals. 
Like the Pitcairn pyroxene, the wollastonite is intergrown 
with calcite and microcline, and the latter often extends some 
distance into the wollastonite crystal. All of the wollas- 
tonite crystals show a distinct basal cleavage, and a less 
perfect one parallel to i-i, and 1-i. There is also a prismatic 
parting parallel to I, which is not mentioned by Dana. Owing 
to the splintery nature of the wollastonite it was impossible to 
section it and determine the optical properties. The simplest 
and commonest form of the crystals examined is a combination 
of the basal pinacoid[c], 0P [001], the orthopinacoid [a], i-i 
[100], the positive unit orthodome (¢), 1-i [101], and the nega- 
tive unit orthodome (v),—1-i [101]. 
