518 The American Naturalist. [June, 
The mineral, when in the groundmass of the rhyolite is often associa- 
ted with a pale rose epidote (withamile) and the common green 
variety, the latter in some cases surrounding the piedmontite. All of 
the epidotes are supposed to be of secondary origin. 
Some American Minerals.—The interesting mineral rowlandite 
from Llano Co., Texas, to which reference has already been made in 
these notes, has recently been described by Hidden and Hillebrand”. 
Its color varies from bottle green to a pale drab green shade. It is 
more vitreous than gadolinite, is transparent in thin splinters and it 
weathers to a waxy brick red substance. The mineral is isotropic. Its 
hardness is 6 and its density 4.515. An analysis gave: 
SiO, X ThO, CeO, La,O, ete. Yt,O,ete. FeO, FeO MnO Cad 
26.04 389 59 5.06 4 47.70 09- 439. GTi 
MgO Alk HO CO, FI PO, . Total—0O—F 
162 25 .24 34 387 tr = 101.12—1.68 = 99.99. 
Disregarding the CO, and CaO and reducing the rare earths to a hypo- 
thetical one with the molecular weight of the yttrium group the for- 
mula becomes Si, Yt, Fe FI,O,, or Fe (YtF), Yt, (Si,O,),. 
Transparent xenotine in small crystals associated with muscovite in a 
quartz pocket is reported by Hidden from near Sulphur Spring, 
Alexander Co., N. C., and a green variety of the same mineral from 
the Brindletown gold district, Burke Co., in the same State. The 
green xenotine has been found only in the gold gravels, forming the 
interior portions of some of the rough brown crystals intermingled 
with the sand. It is thought to be original substance from which the 
brown material was derived by weathering. An analysis of the green 
mineral indicates a complicated composition : 
SiO, ZrO UO, Tho, Al,0O, Fe,O, (La Di),O, (Yt Er),0, CaO P,O, a! 
$46. 195 418 t 77 65 98 56.81 21 3031 06 AF 
In a paper entitled “ Minerological Notes ” Moses" describes pyrite 
crystals from a cavity in limestone at King’s Bridge, N. Y. The 
crystals are octahedral in habit, with the octahedral faces striated par- 
allel to œ 0% and «02. On the diploid and pyritoid faces the stria- 
tions are parallel to their intersections, while the cubic faces are unstri- 
i Tere Pe 1893, p. 208. Cf. also AmER. NAT., 1893, p. 248. 
*Ib., XLV, 1893, p. 488. 
