CONNECTICUT.

A. Olivine-basalt, main flow, Pine Hill, South Britain. Contains plagioclase, pink augite, olivine, and magnetite. The rock is quite fresh.

B. Olivine-basalt, anterior flow, South Britain. Contains plagioclase, uralitized augite, olivine, and magnetite. Rock much altered and containing numerous amygdules of calcite and prehnite, stained by iron. Rocks A and B studied by W. H. Hobbs, who furnishes the petrographic data. Hitherto unpublished. Analyses by W. F. Hillebrand, record No. 1842.

C. Basic pitchstone (tachylyte), from the so-called "ash-bed" northeast of Meriden. Described by Emerson in Bull. Geol. Soc. Amer., vol. 8, p. 77. Analysis by H. N. Stokes, record No. 1641.

NEW YORK.

I. ROCKS OF THE ADIRONDACK REGION.

Collected by J. F. Kemp, who furnishes the petrographic data. A and G are described by Kemp in 19th Ann., Part III, p. 383. The other descriptions are hitherto unpublished. Analyses A and B by George Steiger, record No. 1715; C to G by W. F. Hillebrand, record No. 1717.

A. Wall rock of iron mine near Lincoln Pond, Elizabethtown. Varies from norite to gabbro. Chief minerals, green augite, hypersthene, brown hornblende, plagioclase, and magnetite. Microperthitic feldspar less common. Garnet varies from absence to abundance.

B. Coarse gabbro, top of Whiteface Mountain. A pyroxenic phase of the anorthosite. Contains much labradorite, abundant light-green augite, brown hornblende, shreds of more or less bleached brown biotite, and magnetite.

C. Pyroxenic anorthosite, Elizabethtown. Contains largely labradorite, subordinate light-green augite, less brown hornblende, and a little magnetite.

D. Norite, with close affinity to gabbro. Intrusion in C. Contains labradorite, hypersthene, garnets, green augite, brown hornblende, a little brown biotite, magnetite, and apatite.

E. Diabasic norite or gabbro, Elizabethtown. minerals as D.

Contains the same

F. Gneissoid derivative, by pressure, of E. The same minerals, but with hornblende more abundant.

G. Gabbro, wall rock of Split Rock mine. Contains augite, hypersthene, brown hornblende, garnet, plagioclase, magnetite, and possibly spinel.

ZrO2, Cl, and F not looked for. Cr2O3, Li2O, and SrO present in traces. S is in part, at least, present as pyrrhotite.

2. PERIDOTITE FROM DEWITT, NEAR SYRACUSE.

A rock described by Darton and Kemp, Amer. Journ. Sci., 3d series, vol. 49, p. 456. Contains olivine, partly serpentinized, biotite, and augite, with magnetite, apatite, and perofskite. Possibly a little chromite also. Classed by Kemp as limburgite.

Analysis by H. N. Stokes, record No. 1491. The FeO represents the total iron, because the sulphides present, possibly as pyrrhotite, prevent the separate estimation of the two iron oxides.

NEW JERSEY.

Rocks A, B, and C, described by J. P. Iddings in Bull. 150, pp. 254, 209, 236. Analyses by Eakins, record No. 1299.

A. Basalt, Watchung Mountain, Orange. Contains pyroxene, mostly malacolite, plagioclase, magnetite, and glass, with variable amounts of serpentine or chlorite. The feldspar is partly altered into a mineral which is probably prehnite. P. R. C. 102.

B. Elæolite-syenite, Beemersville. Contains nephelite, orthoclase, ægirite, and biotite, with melanite, sphene, apatite, zircon, and magnetite in smaller amounts. Sodalite is probably present also. P. R. C. 78. C. Minette, Franklin Furnace. Contains alkali-feldspar, biotite, monoclinic pyroxene, magnetite, epidote, calcite, chlorite, apatite, sphene, pyrite, and a little secondary quartz. P. R. C. 91.

D. Nepheline-syenite, Brookville. Collected by N. H. Darton and described by F. L. Ransome in Amer. Journ. Sci., 4th series, vol. 8, p. 417. Contains alkali-feldspars, nepheline largely altered to secondary minerals, brown amphibole, biotite, cancrinite, plagioclase, muscovite, ægirine-augite, apatite, titanite, fluorite, and a few specks of magnetite. Also secondary analcite, sericite, and natrolite (?). Analysis by Steiger, record No. 1807.