K. Banakite dike, head of Lamar River. Monzonose. Contains augite, serpentinized olivine, orthoclase, plagioclase, biotite, magnetite, ilmenite, apatite, and analcite. Adjoins rock B. Analysis by Eakins, No. 1375.

L. Banakite dike, Hoodoo Mountain. Monzonose. Like K, but with amygdaloidal zeolites. Analysis by Eakins, No. 1371.

M. Banakite dike, Ishawooa Canyon, Wyoming. Monzonose. Like K and L, but more feldspathic. Contains a little serpentine, probably from olivine; also possibly analcite or sodalite. Analysis by Eakins, No. 1086.

N. Banakite dike, near head of Stinkingwater River. Monzonose. Like M, but with more serpentine. Analysis by W. H. Melville, record No. 1232.

O. Leucite-banakite lava sheet, southeast fork of Beaverdam Creek. Shoshonose. Overlies rock G. Contains olivine, augite, leucite, feldspars, magnetite, apatite, and a little brown mica. Analysis by Eakins, No. 1378.

P. Earlier unpublished analysis of O, another sample, by J. E. Whitfield, record No. 907.

Q. Quartz-banakite dike, near head of Stinkingwater River. Monzonose. Contains plagioclase, orthoclase, quartz, biotite, magnetite, augite, and a little calcite. Analysis by Melville, No. 1232.

R. Quartz-banakite dike, near Q. Pulaskose. Contains plagioclase, orthoclase, quartz, biotite, magnetite, augite, chlorite, and serpentine. Analysis by Melville, No. 1232.

S. Absarokite, Two Ocean Pass. Kentallenose. Contains augite, olivine, orthoclase, magnetite, serpentine, little biotite, apatite, and an isotropic substance, probably glass. Analysis by J. E. Whitfield, record No. 906.

T. Shoshonite, Beaverdam Creek. Shoshonose. Analysis by Whitfield, No. 907. Probably the rock already represented by analysis G. U. Shoshonite, northeast spur of Sepulchre Mountain. Shoshonose. Contains augite and serpentinized olivine, in a groundmass of plagioclase, orthoclase, augite, magnetite, and apatite. Analysis by Whitfield, No. 908.

V. Shoshonite, Baldy Mountain, Bear Gulch, Montana. Shoshonose. Contains hypersthene, augite, olivine, plagioclase, orthoclase, and magnetite. Analysis by Whitfield, No. 909.

5. MISCELLANEOUS ROCKS. FIRST GROUP.

Collected and investigated by Arnold Hague and J. P. Iddings. A. Black obsidian, Obsidian Cliff. Liparose. Described by Iddings, 7th Ann. Contains microlites of augite and magnetite, with traces of quartz and feldspar. Analysis by J. E. Whitfield, record No. 224.

B. Red obsidian, Obsidian Cliff. Alaskose. Described by Iddings, 7th Ann. Like A, with ferric oxide replacing magnetite. Analysis by Whitfield, No. 223.

C. Obsidian, east of Willow Park. Lassenose. Lassenose. Black and opaque. Described by Iddings, Bull. Phil. Soc. Washington, vol. 12, p. 204. Analysis by Whitfield, No. 222.

D. Lithoidite, Obsidian Cliff. Lassenose. Described by Iddings, Bull. 150, p. 153. Contains quartz and sanidine, with a little magnetite and augite. Analysis by Whitfield, No. 425. P. R. C. 62. E. Rhyolite, Upper Geyser Basin. Liparose. See Iddings, Bull. Phil. Soc. Washington, vol. 12, p. 204. Analysis by F. A. Gooch, record No. 114.

F. Rhyolite, Tower Creek. Toscanose. See Iddings, Bull. Phil. Soc. Washington, vol. 12, p. 204. Analysis by Gooch, No. 115.

G. Rhyolite, "Great Paint Pots." Liparose. Analysis by Gooch, No. 113, hitherto unpublished.

H. Rhyolite, "Elephants Back." Porphyritic obsidian. Tehamose. Analysis by Whitfield, No. 423, hitherto unpublished. Reported by Iddings as containing quartz, sanidine, and a little augite and magnetite, in a glassy, microlitic groundmass.

I. Rhyolite, Mount Sheridan. Tehamose. Composition reported by Iddings as quartz and sanidine, with a little magnetite and augite. Analysis by Whitfield, No. 426, hitherto unpublished.

J. Rhyolite, Madison Plateau. Like I. Near alaskose. Analysis by Whitfield, No. 427, not yet published.

K. Trachytic rhyolite, Elk Creek. Lassenose. Analysis by Whitfield, No. 428, hitherto unpublished. Reported by Iddings as containing sanidine, labradorite, and little biotite, in a groundmass of quartz and alkali feldspar.