56 Lhe West American Scientist. 
the cavity are lined with cacholong, but the bottom of the cavity 
is partly filled in with a white compact chalcedony The interior 
of the crystal is radiated, but is of a dark chocolate color :nd 
almost entirely altered to hematite. 
ZIRCON—This mineral is now mined by the ton in the United 
States, and about $150 per ton is paid for it, because of the earth 
it contains (Zirconia) which is used in the hoods for the new in- 
candescent gas burners. The Zircons are obtained by washing 
out the soil resulting from the decomposition of felspathic rocks. 
OBSIDIAN— Obsidian has been found in British Columbia, but 
it has little value, except for the cheaper jewelery, and is rarely 
used for that purpose. 
PaRIs Exposirion—Messrs. Tiffany & Co. exhibit a collection 
illustrating the occurrence of precious and ornamental stones in 
North America, containing all the more important varieties, in 
their natural state and in cut examples. The 352 labels include 
crystals of gold, gold and silver ornaments from Indian mounds, 
diamonds, rubies, sapphires, topaz, emerald, beryls, garnets, 
tourmalines, zircon crystals, peridot, quartz, amethyst, opal, 
agate, rutile, turquoise, amber and many other minerals not so 
well known to the public as gems. 
Tur QuoisE—Additional evidence of the antiquity of the tur- 
quoise workings of New Mexico and Arizona has been gathered 
by the Hemenway Expedition under the direction of Mr. Frank 
H. Cushing. About ten miles from Tempe, Arizona, a shell en- 
crusted with turquoise and garnet, representing the form of a 
frog, was found in the excavations. 
CHRYSOPHRASE— Beautiful semi-transparent chrysophrase ot 
fine color occurs in Tulare county, California. This gem has also 
been found in Douglas county, Oregon. George: Fe Kunz: 
BBA TOW ad tad 
J. JENNER WerrR—Exhibited a female example of Danais 
plexippus from Custer county, Colorado, to South London 
Entom. Society. This specimen differed from the examples from 
more northern localities, in having all the spots on the black 
apical patch on the fore wings white, instead of fulvous. Mr. 
Wier also exhibited Pieris oleracea, and stated that he had heard 
from Mr. Scudder that this species could be readily distinguished 
from P. Napiin the larval and pupal stages. xtomologist, Feb- 
ruary, 1889; page 52. TD AA 
J. W. DoucLas—Notes on some British and exotic Coccide. 
Ent. Mo. Mag., March, 1889. page 232. Notes on Icerya pur-— 
chasi, partly quoted from: Prof. Riley and Mr. R. T. Lewis (in 
litt.) with figure of the larva of Icerya. Hippodamia ambigua 

