correlations of the marine beds have been made by comparison with it. During the last year F. Noetling,' paleontologist of the Geological Survey of India, has startled geologists in their fancied security, by the statement, based on his later investigations, that the Otoceras beds of India belong to the upper Permian, and are older than the Werfen beds of the Alps. As they lie conformably upon the upper Productus limestone, they represent, according to Noetling, strata of which the equivalents are lacking in the European section. Accordingly he proposes to call the entire Ceratite formation upper Permian, and as a name for the stage he proposes the term Bactrian. If this should prove to

be correct it would throw the Ceratite formation of India, the Proptychites beds of Siberia, and the Meekoceras beds of Idaho and California into the upper Permian.

A. von Kraft, also of the Geological Survey of India, agrees with Noetling, but only as to the Permian age of the Otoceras beds; the upper part of the series where Meekoceras and Flemingites are so abundant he regards as certainly of lower Triassic age. He says that Medlicottia dalailamae Diener of the Otoceras beds is identical with M. wynnei Waagen of the upper Productus limestone, and that Cyclolobus oldhami Waagen and Xenaspis carbonaria Waagen, which in the Salt Range occur in the middle Productus limestone, in the Himalayas occur in the Kuling Productus shales only twenty or thirty feet below the Otoceras beds. This would make the bottom of the Otoceras beds (the lower Ceratite limestone) the equivalent of the upper Productus limestone of the Permian. This argument, however, might work both ways, for it would just as well prove that the upper Productus limestone belonged to the base of the Trias, since in any case the division line must be arbitrary. Nor would the finding of Productus itself in the Otoceras beds prove them to be

'Geol. Surv. of India, General Rept. for 1899 (1900). Notes on the Relationship between the Productus Limestone and the Ceratite Formation of the Salt Range, and Neues Jahrbuch für Min. Geol. und Pal., 1900. Bd. I, p. 139, Ueber die Auffindung von Otoceras sp. in der Salt Range.

'Centralblatt für Min. Geol. und Pal. Bd. II, 1901, p. 275, Ueber das Permische Alter der Otoceras-Stufe des Himalyas.

Paleozoic, for if Otoceras, Medlicottia, Xenodiscus, and Xenaspis can range into the Mesozoic, there is no known reason why Productus should not have done so. Indeed, Xenaspis and Xenodiscus range up into the Middle Trias, associated with faunas characteristic of the Muschelkalk.

C. Diener meets Noetling's argument by stating that if the Ceratite formation of India is not of Lower Triassic age, then we have nowhere in the world a strictly marine equivalent of the Werfen beds, and that we have the anomaly of Middle Triassic beds lying conformably on Permian. He shows that the marine Permian of the Alps, which lies below the Werfen beds, has not the fauna of the Otoceras beds, but one analogous to that of the Productus limestone. Diener admits that the Otoceras horizon is older than the fossil ferous portion of the Werfen beds, but thinks that the rule of priority of reference must be followed, where there are no paleontologic grounds against it and many for it. He also cites a recent paper by A. Bittner to show that there is found in the Proptychites beds of Ussuri a typical pelecypod and brachiopod fauna of Werfen character; it must be admitted, however, that this fauna was not found with the ammonites, and might belong considerably above them.

The most direct comparison with the European Trias has been made by Lukas Waagen,3 who shows that in the Ceratite marls and the Ceratite sandstone of India he has identified a number of pelecypods identical with forms characteristic of middle and upper Werfen beds of the Alps. This leaves the question about as A. von Kraft stated it. The Ceratite formation, from the Ceratite marls up, certainly belongs to the Lower Trias, since the Werfen beds are the type, while the Otoceras beds of the Himalayas, or their equivalent, the lower Ceratite limestone, may belong to the upper Permian. But the fauna of

'Centralblatt für Min. Geol. und Pal. Bd. I, 1900, p. 1, “Ueber die Grenze des Perm- und Triassystems, etc."

2 Mém. Com. Geol. St. Petersbourg, Vol. VII, 1899, " Verstein. aus den Trias-Ablagerungen des Süd-Ussuri Gebietes in der Ostsibirischen Küstenprovinz.

3 Centralblatt für Min. Geol. und Pal. Bd. I, 1900, p. 285.

the lower Ceratite limestone and that of the Ceratite marls are so similar that a separation of the two is out of the question, and even the genus Otoceras is found in the latter. Now, since these doubtful beds are younger than any accepted Permian, and older than any authentic Trias, they might with equal propriety be assigned to either, and we shall have to extend one or the other system to include them. The question will have to be decided either by paleontologic relationship, or by priority of reference. The Otoceras beds contain Meekoceras, Proptychites, Ophiceras, and several other ammonite genera that have never been found in the Paleozoic; they contain also Medlicottia and Otoceras that are more characteristic of Upper Permian; but they lack the Productidae and Orthidae that characterize the Permian formation. Thus the paleontologic evidence is about equal in favor of a reference to either Paleozoic or Mesozoic. But the geologists that described the fauna of the doubtful beds have almost unanimously referred them to the Lower Trias, and this must be the final verdict.

- The fauna of the Meekoceras beds of Idaho and California is most intimately related to that of the Ceratite marls and the lower part of the Ceratite sandstone of India, with most of the genera in common, and several species that seem to be identical. And although the writer has searched carefully for Otoceras in both places, no trace either of this genus or of Medlicottia was found. It seems likely, then, that even if the bottom of the Ceratite formation should be cut off from the Trias and assigned to the Permian, this change would not affect the nomenclature of our American formations that are now considered as the bottom of the Mesozoic series, and the Meekoceras beds will stand as the type of the marine Lower Trias, where White and Hyatt placed them in 1879. The real transition from Paleozoic to Mesozoic must be sought in the conformable series below the Meekoceras beds, and above the Fusulina limestone.

STANFORD UNIVERSITY,

California.

JAMES PERRIN SMITH.

STUDIES FOR STUDENTS

THE CONSTITUENTS OF METEORITES. II

Glass. This is an abundant constituent of the stone meteorites, few if any being entirely without it. It is variously distributed, occurring now as vein matter, now scattered through the substance of chondri, now enclosed in the substance of a single mineral, and now enclosing various minerals.

In the Parnallee, Mezo-Madaras, Chassigny, Farmington and a few other meteorites it has been described as forming a network in which the other minerals are imbedded. Its ocurrence in this manner is rare, however, it playing usually a merely accessory part. It chiefly abounds as inclusions and intergrowths in chrysolite, taking in this association a great variety of forms. Other minerals too, frequently have inclusions of glass. It may occur in fragments of considerable size or the particles may be of a dustlike minuteness.

By all

Its abundance in chondri has already been mentioned. these occurrences a rapid crystallization or cooling of the meteorite substance is strongly indicated. Like the glass of terrestrial lavas it seems to be the result of cooling so rapid as to prevent differentiation and orderly crystallization of the magma. The especial abundance of glass in meteoritic chrysolite, the least fusible and therefore the earliest cooling ingredient further favors this conclusion.

The prevailing color of the glass of meteorites is brown. Much is however colorless and some occurs so dark as to be opaque. Grayish and greenish tones occur but are rare.

Chromite. Nearly all stone meteorites give on analysis a small percentage of chromium which is usually considered as being present in the form of chromite, FeO, Cr,O,. The mineral is not so abundant in the iron and iron-stone meteorites

but has been detected in several and in the Coahuila irons occurs in nodules of considerable size (17mm x 12mm).

It is identical with terrestrial chromite in composition and properties. Not being acted upon by acids, it may be readily distinguished from daubréelite. It is generally non-magnetic, but sometimes feebly magnetic. Where crystals occur they are commonly octahedrons, sometimes modified by other forms.

Amorphous carbon.—Meteorites of the group known as carbonaceous meteorites, as well as some others, are permeated by a dull-black pulverulent coloring matter which is usually left as a residue on treatment of the meteorite with acid. This residue sometimes amounts to from 2-4.5 per cent. of the mass.

A residue similar in character though smaller in amount is likewise found after dissolving many of the iron meteorites. These residues on being heated in air glow, usually become lighter in color and give off carbon dioxide. They must therefore be considered practically pure carbon.

Berzelius and Wöhler believed this carbon to have originated so far as the carbonaceous meteorites are concerned, from the decomposition of the hydrocarbons of the latter. In this respect they regarded it analogous to terrestrial humus, though of very different origin. Smith considered it similar in origin to the graphite of iron meteorites and Weinschenk believes it similar to one of the forms of carbon produced in the making of cast iron. No indications that it had an organic origin have ever been discovered.

Diamond.-The existence of diamonds has been definitely proven in only two meteorites, those of Cañon Diablo and NowoUrei. Diamonds have, however, also been reported from the irons of Magura and Smithville and the stone of Carcote. The diamonds of the Cañon Diablo meteorites have been most studied. Here they are found as minute particles or dust left as a residue after dissolving the meteorite in acid. The particles rarely exceed 1⁄2" mm in diameter. They are usually brown to black in color but sometimes are colorless and transparent. They accompany graphite, amorphous carbon and often troilite