The granitic rocks included granite, gneisses, syenites and norite. This series only inadequately represented the New York granites. Among the most striking examples shown were the coarse grained red granite from Grindstone island in the St. Lawrence river, the Mohican granite from Peekskill, Westchester county, which is being extensively used in the Cathedral of St. John the Divine in New York city, and the dark green labradorite rock known as the Ausable granite from Keeseville, Essex county. There are many interesting granite deposits, especially in the Adirondack region, which have not been developed. MARBLES The marbles included some fine examples of decorative stone from South Dover, Dutchess county, the black marble from Glens Falls, monumental and building marbles from Gouverneur, St. Lawrence county, and white building marbles from southeastern New York. LIMESTONES Limestones of excellent quality are quarried in a great number of localities and were well represented, some of them showing as fine a polished surface as the true marbles. SANDSTONES The State is also rich in sandstones of good quality. The Potsdam sandstone forms an almost complete belt around the Adirondacks and is an excellent building stone. Its color is from white to pale red, and in many places it is an extremely hard quartzite. Specimens were shown from Potsdam, St. Lawrence county. The white sandstones of Washington county have been extensively used for refractory purposes in the manufacture of steel, being almost free from iron. The Medina sandstones are quarried in the neighborhood of Medina, Albion and Lockport. While a pure white stone occurs at Lewiston, the Medina stone is generally of a pinkish red color. It is extensively used as a building stone, particularly in Buffalo and Rochester. It is valuable for paving, curbing and flagging. The Medina Sandstone Company exhibited a piece of wall work to show the various methods of finish, including a finely carved lintel. A number of cubes were exhibited from various quarries. The sandstones of southern New York occurring in the rocks of Devonian age are generally fine grained and blue or greenish in color and are known as bluestones. Most of the quarries are in the counties of Greene, Ulster, Broome, Delaware and Sullivan. They are described in New York State Museum Bulletin 61 by Harold T. Dickinson. There is a great variety in color and physical properties of stone from these quarries. It is used as building stone and for trimming, and some of it is especially valuable for large platforms. A large proportion of the output is in the form of flagging and curbstone. The Hudson River Bluestone Company exhibited a piece of wall built into the base of the pyramidal stand holding the sandstone cubes. This was designed to show the ease with which it can be worked and included some finely carved lettering. The main entrance to the exhibit was paved with flags and tiles of this material. SLATE