There are two types of meteorites, those made wholly or largely of iron with some nickel, and appearing like great chunks of iron, and those which are stony and resemble a granite boulder. In collections the first sort, _i.e._ iron meteorites, are most abundantly represented, because most easily recognized when found. They consist of masses of iron and nickel with small amounts of other elements, ranging in size from the Cape York meteorite, which fell in northern Greenland in 1894 and was later brought by Peary to the American Museum, and weighs some 36 tons, down to small grains as small as a grain of wheat. The largest one which has fallen in the United States was the Willamette meteorite weighing some 15 tons, and falling 19 miles south of Portland, Oregon. These and all iron meteorites have the iron in crystalline form which is readily seen if the meteorite is cut, and the surface thus made polished, then etched with acid, which is put on and quickly washed off. Every meteorite has its particular pattern, as illustrated on Plate 72, and by these patterns can be identified. Meteorites have a high value and are eagerly sought by certain large institutions and collectors. Since the crystalline structure is so characteristic of each fall, when a new meteorite is found, it is usually cut in two, and one part retained by the finder or some institution; while the other part is cut into small pieces, an inch or two on a side and a quarter of an inch thick, but each large enough to show the characteristic pattern. These are distributed largely by sale to other collectors. Thus a great meteorite collection consists of a few large meteorites and a great many small portions of other meteorites. The second type of meteorite is the stony meteorite. Where meteorites have been located as they fell and recovered, the majority of them were of this type, so that probably more than half of the meteorites which fall are of the stony type. However when the stony meteorite is exposed to weathering it takes only a very short time before the surface is eroded off and then such a meteorite looks like any other boulder and probably most of them fail to be recognized, and so have been lost. Because they have so much greater variety, they are in many ways of greater interest than the iron type. It is desirable that every one have his eye out for meteorites, and when found it is desirable that the fact should be reported to some one of the great institutions which collect them, such as the National Museum in Washington, or the American Museum in New York. Each one should be on record even if it is desired to keep it in a private collection. Fossils