4. MISCELLANEOUS ROCKS.

A. Typical diabase, Rocky Ridge. Analyzed for J. S. Diller, but not described. Analysis by E. A. Schneider, record No. 1370.

B. Ottrelite-phyllite rock, Liberty, Frederick County. Analyzed for S. H. Williams, but not described.

C. Ottrelite separated from B. Analyses B and C by L. G. Eakins, record No. 1349.

D. Quartz-schist, Shoemaker quarry, near Stevenson Station, Green Spring Valley. Described by Bayley in Bull. 150, p. 302. Contains quartz, muscovite, occasional tourmalines, microcline, zircon, and iron stains. Analysis by Schneider, No. 1370. P. R. C. 119.

E. Mica separated from D. Analysis by Schneider, No. 1377.

F. Sericite-schist, Ladiesburg. Described by Bayley in Bull. 150, p. 317. Contains quartz, sericite, chlorite, a mineral thought to be kaolin, zircon, iron oxide, and rutile. Analysis by George Steiger, record No. 1600. P. R. C. 126.

G. Another sample of F. Analysis by Schneider, No. 1370.

VIRGINIA.

A. Andesite, 34 miles east of Front Royal. Described by Keith in 14th Ann., p. 305. Intermediate between diabase and quartz-porphyry. Contains plagioclase, quartz, magnetite, ilmenite, and a little epidote. Analysis by George Steiger, record No. 1450.

B. Porphyritic felsite or felsophyre, forks of Straight Creek, 3 miles ENE. of Monterey. Described by Darton and Keith in Am. Journ. Sci., 4th series, vol. 6, p. 305. Contains phenocrysts of biotite, orthoclase, and plagioclase, the mica and feldspar being about equal in amount. In the groundmass are feldspar, quartz, magnetite, or ilmenite, and a little secondary chlorite with less muscovite. No glass. Analysis by Hillebrand, record No. 1665.

NORTH CAROLINA.

Rocks A to F collected by Arthur Keith, who f .rnishes the petrographic data. Analyses B, C, D, and E by W. F. Hillebrand, record No. 1707. Analyses A and F by H. N. Stokes, record No. 1710.

A. Porphyritic rhyolite, 2 miles west of Barmers Elk, Watauga County. Contains orthoclase and plagioclase, with less quartz, epidote, chlorite, and pyrite.

B. Quartz-porphyry, 24 miles northwest of Blowing Rock, Watauga County. Contains quartz and orthoclase, with subordinate sericite, chlorite, and biotite.

C. Diorite, east end of Hump Mountain, Mitchell County. Contains plagioclase, orthoclase, and hornblende, with less quartz, biotite, magnetite, and garnet.

D. Garnetiferous diabase, 14 miles southeast of Cranberry. Contains plagioclase and hornblende, with less garnet, biotite, and magnetite.

E. Epidote-chlorite-schist, mile northeast of Montezuma, Mitchell County. Contains epidote and feldspar, with less chlorite, hornblende, and magnetite.

F. Metamorphosed amygdaloid, 3 miles southeast of Boone, Watauga County. Contains orthoclase and plagioclase, with less sericite, chlorite, and magnetite.

G. Pyroxenite, var. websterite, from Webster. Described by Williams, Amer. Geologist, vol. 6, p. 35. Consists of diopside and bronzite. Analysis by E. A. Schneider, record No. 1096. Material dried at 105°. P. R. C. 388.

H. Spherulitic rhyolite, Sam Christian gold mine, Montgomery County. Described by Diller, Amer. Journ. Sci., 4th ser., vol. 7, p. 337. The rock of the supposed fossil, palæotrochis. Contains feldspar and quartz, with a little biotite and sericite. Analysis by Hillebrand, record No. 1796.

The following rocks from Corundum Hill were collected, analyzed, and described by T. M. Chatard, Bull. 42, p. 45.

I. Altered gneiss. Made up of micaceous scales, with grains of quartz and some earthy matter. Record No. 238.

J. Dunite. Olivine rock containing a little chromite. Record No. 256.

K, L. Yellow, clay-like alterations of dunite. Record Nos. 254, 255. Other analyses of altered rocks are given in the paper, and also analyses of associated minerals.