704. HENRY S. WASHINGTON 
grorudose, while the other two fall well within grorudose, II.4.1.3, 
B being intermediate toward liparose and pantellerose. Acmite 
predominates strongly among the femic minerals, and the amount 
of sodium metasilicate is very small or nothing, in which respect 
this type of pantellerite differs from that next to be described. 
Mode.—Owing to the fineness of the grain the mode cannot 
be determined by optical means but can be recalculated from the 
norm, the same assumption being made as to the cossyrite as before. 
A B 
Quartz cp ears nn ae 28 Quartz. 2: 5)5.5. ese Oe 20 
OrcAl ari tpt ee pee leah ag: 45 OrjAbe: A.) way 3a ee 63 
Fast AU Oy Mer see cae Nella orig ey aim aa eet 17 NC PATIte-AUPIL eC en ee eee 
Cossymites onan ee SNE (os 10 Cossyritée icine ba 
This type, being holocrystalline, may be regarded as typical 
pantellerite, the cenotypal equivalent of Brégger’s grorudite, the 
analyses of which are closely similar. 
HYALO-PANTELLERITE, KHAGIAR TYPE (KHAGIARAL VARINGOSE AND 
GRORUDOSE) 
Occurrence.—This type is, in general, later than the preceding, 
belonging to the last period of the second phase after the tilting 
of the Montagna Grande block and before the eruption of basalts. 
In certain localities, as at Sant’ Elmo, Cuddia Nera, and, in the 
south of the island, flows of the Santelmal type show streaks and 
patches of this glassy black type. The cones and flows of this 
type are found around the tilted Montagna Grande block, at 
Cuddie Randazzo and Gelfiser, with their respective great flows, 
at the north, Gelkhamar and Sciuvechi at the northwest, the two 
small Monti Gibile to the west, Fosso del Russo and the lavas of 
Rione Benimingallo to the south, and those of Rioni Mueggine 
and Khamma to the east. These lava flows are of the aa type, 
the blocks being generally angular. 
Megascopic characters—The specimens from most of the 
occurrences are very uniform. They are black, highly vitreous 
rocks, composed of a pure black, generally lustrous, glass ground- 
mass, which in some specimens is locally slightly iridescent due to 
incipient alteration. In the specimen from Cantina Ziton the 
glassy groundmass is dull and somewhat waxy in luster. This 
