F. Hornblende-mica-andesite.

Yellowstonose. Contains plagioclase, hornblende, biotite, and magnetite. Analysis by Whitfield, No. 924.

G. Hornblende-mica-andesite. Dacose. Contains plagioclase, hornblende, and biotite. Analysis by Chatard, No. 712.

H. Dacite. Yellowstonose. Contains plagioclase, hornblende, biotite, and quartz. Analysis by Whitfield, No. 830.

I. Dacite. Lassenose. Minerals as in H. Analysis by L. G. Eakins, record No. 1135.

J. Andesite-breccia. Lassenose. Not in paper cited. See Mon. XXXII, Pt. II. Analysis by Chatard, No. 712. Reported by Iddings as hornblende-mica-andesite, containing hornblende, plagioclase, quartz, biotite, and a little magnetite.

3. ABSAROKA RANGE.

1. CRANDALL BASIN.

Rocks described by Iddings in Mon. XXXII, Pt. II. The analyses also appeared in Bull. Phil. Soc. Washington, vol. 12, p. 204.

A. Gabbro-porphyry, Hurricane Ridge. Camptonose. Contains augite, plagioclase, hypersthene, biotite, magnetite, and a little olivine. Analysis by L. G. Eakins, record No. 1089.

B. Basalt flow, north side of Timber Creek. Andose. Rich in olivine, augite, and magnetite. Analysis by Eakins, No. 1087.

C. Basalt dike, ridge south of Hurricane Ridge. Shoshonose. Like B. Contains also labradorite and a little orthoclase. Analysis by Eakins, No. 1087.

D. Mica-gabbro-porphyry, Hurricane Ridge. Camptonose. Contains plagioclase, augite, hypersthene, biotite, and magnetite. Analysis by Eakins, No. 1089.

E. Mica-gabbro, Hurricane Ridge. Andose. Like D, with some orthoclase and a little quartz and olivine. Analysis by Eakins, No. 1089.

F. Basalt-glass-breccia, ridge south of Indian Peak. Andose. A glass showing crystals of olivine, augite, plagioclase, and magnetite. Analysis by Eakins, No. 1087.

G. Orthoclase-gabbro-diorite, rich in mica, Hurricane Ridge. And ose. Contains orthoclase, plagioclase, quartz, biotite, augite, hypersthene, magnetite, and hornblende. Analysis by Eakins, No. 1089. H. Another sample, like G. Andose. Same analyst and record number.

I. Dioritic facies of gabbro, Hurricane Ridge. Andose. Very feldspathic. Same analyst and number.

J. Monzonite, Hurricane Ridge. Andose. Contains orthoclase, plagioclase, biotite, augite, hypersthene, and magnetite. Analysis by W. H. Melville, record No. 1233.

K. Augite-andesite-porphyry. Andose. Intrusive sheet, Hurricane Ridge. Analysis by Eakins, No. 1088. Contains plagioclase, augite, hypersthene, magnetite, biotite, quartz, and microscopic orthoclase.

L. Hornblende-mica-andesite-porphyry dike, ridge south of Hurricane Ridge. Tonalose. Contains plagioclase, hornblende, biotite, augite, hypersthene, and magnetite, with a little chlorite or serpentine. Analysis by Eakins, No. 1087.

Yellowstonose.

M. Quartz - diorite - porphyry, Hurricane Ridge. Contains plagioclase, orthoclase, quartz, augite, hypersthene, magnetite, and a little biotite. Analysis by Melville, No. 1234.

N. Quartz-mica-diorite, Hurricane Ridge. Adamellose. Contains andesine, orthoclase, quartz, biotite, hornblende, magnetite, and a little pyroxene. Analysis by Melville, No. 1234.

O. Quartz-mica-diorite-porphyry, Hurricane Ridge. Toscanose. Contains andesine, orthoclase, quartz, and biotite. Analysis by Melville, No. 1234.

P. Aplite dike, Hurricane Ridge. Toscanose. Contains quartz, orthoclase, oligoclase, biotite, magnetite, some chlorite, and a little hornblende. Analysis by Eakins, No. 1088.

2. SUNLIGHT INTRUSIVES.

Descriptions, hitherto unpublished, supplied by Arnold Hague and T. A. Jaggar, jr. Analyses A, B, and C by W. F. Hillebrand, record No. 1801; D by H. N. Stokes, No. 1804.

A. Quartz-syenite, Copper Creek Basin. Laurvikose. Contains biotite, hornblende, epidote, orthoclase, augite, titanite, magnetite, and apatite. Hornblende very pale in color.

B. Syenite-porphyry, Sulphur Creek Basin. Lassenose. Contains oligoclase and biotite, in a groundmass of quartz and feldspar.

C. Augite-syenite-porphyry, Copper Creek Basin. Laureikose. Contains augite, biotite, orthoclase, a little hornblende, and quartz. D. Gabbro, southwest of Beams Hill, Sunlight Valley. Andose. Contains plagioclase, pyroxene, magnetite, apatite, and a little biotite.