stage 
on 
1888.] 1 79 (Hunt. 
Pyrites of the same system, but are here divided on chemical grounds. 
The tribe of the Pyritoideee may be divided into two genera, the harder 
designated as Pyrites with H = 5.5 —6; 0 =—3.8 — 4.5, includes cubic 
and prismatic iron pyrites, with linneite, siegenite, carrolite and laurite ; 
while the genus Pyritinus, H = 3.5 — 4.0; v 4.5 — 5.5, embraces troilite, 
pyrrhotite, allabandite, millerite, pentlandite, chalcopyrite, cubanite, and 
probably stannipyrite. 
(5.) The tribe of Smaltoidez includes the various arsenids of cobalt, 
nickel, and iron, of which leucopyrite and smaltite are representatives, 
and which we have included in the genus Smaltites, with H = 5 — 6;0 = 
3.6 — 4.5. The arsenids of copper, with less hardness and a higher value 
for v, will form a distinct genus, Algodonites. Closely related to Smal- 
tites is the antimonial species, breithauptite; while the antimonid of 
copper, horsfordite, and apparently dyscrasite, are near to Algodonites. 
(6.) The tribe of Arsenopyritoidex, embracing the genus Arsenopyrites, 
includes the compounds of sulphid of arsenic with sulphids of iron, 
cobalt and nickel, of which arsenopyrite or mispickel is a type, H=5—6; 
© = 2.9 — 3.5. Near to these are some little known double sulphids 
holding antimony and bismuth, as ullmannite, corynite, alloclasite and 
grunauite. 
(7.) Passing now to the suborder Spatometallinea, we have in the tribe 
Spatometalloides those forms of phosphorus and of selenium which are 
wanting in the inetallic characters, including the colorless and the ordi- 
nary red phosphorus, apparently two forms of selenium, and the various 
known species of sulphur. 
(8.) The tribe Sphaleroidex includes the genus Sphalerites, embracing 
sphalerite, wurtzite, christophite, greenockite, hauerite, oldhamite, and 
cinnabar, having H = 2.5 —4.0; 0 =6—¥7. Here also belong the red 
antimony sulphid, metastibnite,* and the arsenical sulphids, realgar and 
orpiment. 
(9.) The tribe Proustoides includes the genus Pyrargyrites, under which 
we may include, in two subgenera, both the arsenical and the antimonial 
red silver ores, including proustite, pyrargyrite, miargyrite, etc.; with 
H=2—3;v=8-—49. In this tribe also are included the arsenical and 
the antimonial forms of fahlerz as members of a genus, Tennantites, in 
which moreover are placed, binnite, dufrenoysite, livingstonite, etc., 
having H = 3.5 — 4.5; 0 = 6.5 — 77.5. 
The following table gives a synoptical view of the tribes and genera 
above proposed for the order of the Metallata. Further studies may prob- 
ably show reasons for further subdivision of some of these genera, and 
for the establishment of new ones. 
* The native red sulphid of antimony, Sh2S3, occurs abundantly as an amorphous 
deposit from thermal alkaline sulphurous waters, with sulphids of arsenic and cinnabar, 
at Steamboat Springs, Washoe county, Nevada, according to a private communication 
from Dr. G. F. Becker, who suggests the name of metastibnite. 
