158 The American Naturalist. [March, 
course of a paper on the Huronian rocks from Sudbury, 
Canada, Bonney^ describes altered feldspar fragments in a 
conglomerate, that have given rise to flakes of mica and 
interlocking grains of quartz. He points out that the same 
change on a larger scale might produce a gneiss — a result 
which has already been indicated by Van Hise.' — A rock 
composed entirely of a mosaic of hornblende and biotite is 
mentioned by Horton' as having been collected at Dosky 
Sound, New Zealand. — Jade has been found by Von Fellen- 
berg' on the contact between limestone and serpentine on the 
Pizzo Lunghino, near the Maloja Pass in the Alps. 
MiNERALOGICAL NEWS.— In a Bulletin of the New York 
State Museum' F. L. Nason describes some fine crystals of 
brown tourmaline from Newcomb, Essex Co., N. Y. o{ pyroxene 
from Ticonderoga in the same county, and of some calcites co\- 
lected by the late Prof. E. Emmons at Rossie, St. Lawrence 
Co. The brown tourmalines occur in Laurentian limestone, 
and present in general the features of the well-known Gouver- 
neur mineral. They are associated with graphite, apatite, 
sphene, wernerite, quartz, zircon, muscovite, albite, tremolite, 
pyroxene and pyrite. Some of the crystals are of large size 
and others are so flawless as to have yielded fine gem material. 
A characteristic grouping is that in which a number of paral- 
lel growths are terminated at one end by a form common to 
the entire group, while at the other end each individual has an 
independent termination. Some of the spJicnes exhale a feted 
odor when struck, and many of them include rutile needles with 
a distinct crystalline form. Dipyr crystals of large size are 
glassy or transparent and enclose crystals of sphene and 
opaque acicular inclusions arranged with their long axis paral- 
lel to the c axis of the dipyr. The c^/czV^ crystals from Rossie 
are remarkable for the fact that they are all twins. The most 
common twinning plane is<^P. Twins parallel to 00 P are also 
quite frequent. Often trillings occur in which two of the crys- 
tals are twinned according to one law, and are twinned with 
reference to the third crystal in accordance with the second 
law. One set of rhombohedral faces is smooth and glistening 
while the second set is rough. The pyroxenes are from a vem 
1 ib. Feb. 1888. p. 32. 
2 Amer. Jour. Sci. xxxi. p. 453- American Xati'ramst, Aug. 1886. p. 723- 
