exceeds that of any of the species of this group. The apex of the median V is not very prominent. Third superior premolar with a rudiment of the anterior and posterior basal lobes; internal lobe not large, conic. Fourth not wider than first true molar, which equals the second and exceeds the third in size. An external cingulum on the true molars, none on the premolars. Probable inferior true molars with anterior and posterior median 1 cusplets. Length of base of four last molars, .020; width of base of P-m. III .006; length of do., .005, do. of P-m. IV, .008; length of do., .007. Diameters of M. II, anteroposterior, .005; transverse, .0095. From the Lowest Puerco. D. Baldwin.-E. D. Cope.

SOME NEW FORMS FROM THE PUERCO EOCENE.-Mioclænus protogonioides, sp. nov. The largest species of the genus, represented by the superior true molars. It is an exaggerated form of the M. subtrigonus. The internal angle of the V, as well as the intermediate tubercles at the ends of its limbs, are distinct. Cingula extending entirely round the crown, the posterior with a small tubercle on the M. 11 as in A. subtrigonus; none on M. 111, which is .75 the area of the M. 11. Diameters M. II, anteroposterior, .008; transverse, .010. Diameters M. III, anteroposterior, .007, transverse, .009. From the Lowest Puerco of New Mexico, D. Baldwin.

Mioclanus opisthacus, sp. nov.- The species of this genus brought thus far from the Puerco formation have no internal. cusp, but a ridge on the internal side of the heel of the inferior true molar teeth. The M. brachystomus of the Wasatch has such a cusp. The present species from the Puerco also possesses this cusp. It differs from the M. brachystomus in its much larger size and more robust premolars. The latter are, however, less robust than in M. turgidus and have an oval anteroposterior section. The fourth has a small heel, but no anterior basal lobe. The true molars are of subequal size and not smaller than the premolars. No anterior inner nor posterior median cusps. Length of last four molars, .025; do. of P-m. iv, .006; of last true molar, 0065. Depth of ramus at M. II, .01 16. Three individuals.

The

Mioclonus baldwini, sp. nov.-The description of the last species applies to this one in many respects, including the posterior inner lobe of the inferior true molars, but the size is less, and the last inferior molar is niaterially smaller. There is also a well defined anterior internal cusp on the second true molar. ramus becomes quite slender anteriorly. Length of last six molars, .035; do. of last four, .022; do. of P-m. IV, .0057; do. of M. I, .0053; do. of M. 111, .0055. Dedicated to D. Baldwin, the discoverer of the Puerco fauna.

Protogonia plicifera, sp. nov.-This, the second species of the genus, differs from its congener, P. subquadrata, in that the inter

nal cusp of the fourth superior premolar is connected with the anterior and posterior cingula by strong ridges, becoming thus the apex of a V. In the P. subquadrata it is a simple cone. Antero-external basal lobe distinct, intermediate lobe obsolete. The true molars are like those of the P. subquadrata, but all the molars are of smaller size. Length of P-m. IV, plus M II and M. III, 0215; diameters P-m. IV; anteroposterior, .006; transverse, .007; do. of M. II, .0095 and .008. D. Baldwin.

Dissacus carnifex, sp. nov.-This creodont differs from its only congener in its greater size, and in the presence of an anterior basal lobe on the third inferior premolar. This is wanting in D. navajovius. As compared with the latter the six inferior molars are as long as its seven, and the mandibular ramus is much deeper. Like it the P-m. IV and the true molars have an anterior basal tubercle: and the last two true molars have an internal supplementary cusp. After the Sarcothraustes antiquus, the largest flesh-eater of the Puerco. Length of last six molars, .075; of true molars, .038; of P-m. IV, 0125; of M. 11, .01353 of M. III, .0130. Depth of ramus at M. II, .029. Upper Puerco, D. Baldwin.-E. D. Cope.

GEOLOGICAL NEWS-The July number of the American Fournal of Science contains a succinct account of the phenomena of metalliferous vein formation now in progress at Sulphur Bank, near Clear lake, Cal., including a description of the geology of the vicinity, by Professor Joseph Le Conte. To the same magazine Rev. A. A. Young contributes observations on the crystallized sands of the Potsdam sandstone of Wisconsin; and G. K. Gilbert writes upon the origin of jointed structure, combating the theory of Professor John Le Conte, who in the March number of the same magazine explains the jointed structure of the Quaternary clays of the Great Salt Lake desert by referring it to the same category with shrinkage cracks observed in recent Californian alluvial deposits. Shrinkage cracks form four to seven sided irregular masses, the included angles.varying greatly, whereas the joints of indurated rocks are characterized by parallelism, and the lines of two systems of joints cross each other, which is not the case in shrinkage cracks. Mr. Gilbert then takes up the theory which classes joints with slaty cleavage, and attributes them to lateral compression. As it appears improbable that a broad sheet of fresh-water sediments, so fresh that the shoretrace of the formative lake has scarcely been impaired by the weather, should have been laterally compressed in two directions nearly at right angles to each other so as to form the two systems of joints which exist in it, and as, moreover, only a single system of joints exists in the Triassic and Jurassic sandstones of the Colorado plateaus, Mr. Gilbert dismisses this theory also as untenable, and regards the question as still an open one. The

Report upon the Geology and Mining Industry of Leadville, Col., by S. F. Emmons, contains thorough details of the Paleozoic and eruptive Mesozoic rocks of the district, and of the ores, which principally occur underneath a porphyry sheet and chiefly in cavities penetrating the "Blue" limestone, the lowest member of the carboniferous.

MINERALOGY.'

CHROME TOURMALINE. Cossa and Arzruni describe in the Zeitschrift fur Krystallographie a new variety of tourmaline, in which chromic oxide replaces a portion of the alumina. The tourmaline, of a deep green color, occurs in deposits of chromic iron in the Ural mountains. The crystals have a beautiful dichroism, appearing, when viewed by daylight, yellow brown, parallel to the optic axis, and blue-green at right angles to the axis. Viewed by lamplight the yellow-brown color changes to rubyred, and the green color nearly disappears. The result is, that the crystals are green by daylight and intense red by lamplighta phenomenon shared by alexandrite.

The chrome tourmaline has a specific gravity of 3.120. Before the blowpipe it melts somewhat easily to a grayish-white, opaque bead. With borax and salt of phosphorus it gives a fine green bead, and in the latter flux a skeleton of silica. It is only decomposed by acids after fusion. The analysis was as follows: Si0, Bo, Al,0, CrO, FeO MgO CaO NaO HO F

36.79 9.51 30.51 10.86 2.91 4.47 .72 1.36 2.25 .65 = 100.08 It is to be classed in the third group of tourmalines of Rammelsberg's classification.

PARAFFINE IN LAVA.-O. Silvestri has found that the basaltic lava in the neighborhood of Etna, contains small geodes filled with solid crystallized paraffine. The paraffine is in large translucent plates of waxy appearance and yellowish-white color, with a melting point of 56°. It is soluble in ether and in boiling alcohol.

NEW LOCALITIES. A. Schmidt describes small transparent crystals of newberyite from Mejellones, Chili. They occur in crevices in guano, and having bright lustrous faces, could be accurately measured in the reflecting goniometer. They are orthorhombic in tabular crystals, with a hardness somewhat more than 3, and a specific gravity of about 2.10. Newberyite had previously been found in Victoria, Australia.

Damour gives an analysis of fuchsite from the Urals, and Arzruni describes its physical properties.

Mendozite, a sodium alum, occurs in the province of Idzumo, Japan, in considerable quantity, as an efflorescence upon albite.

Edited by Professor H. CARVILL LEWIS, Academy or Natural Sciences, Philadelphia, to whom communications, papers for review, etc., should be sent.

It is found in two forms, the one massive, finely fibrous, grayishwhite and translucent; the other as friable opaque tears slightly colored by iron salts. It contains, as shown by Dr. Divers, twenty-four molecules of water, and is thus of the normal type.

A RELATION BETWEEN THE OPTICAL AND CHEMICAL PROPERTIES OF PYROXENE AND AMPHIBOLE.-F. J. Wiik has found a very interesting relation between the optical and chemical properties of the pyroxenes and amphiboles of Finland. The angle between the axes of greatest and least elasticity has a direct relation to the amount of ferrous oxide in pyroxene or the amount of alumina in amphibole, the angle becoming larger as the percentage of these substances increases.

Specimens from a large number of localities were examined with unvarying result. The following are examples:

NEW MINERALS.-Two new minerals from Wermland, Sweden, are described by Igelström:

Manganbrucite.-This is a massive, uncleavable substance of a yellow or brownish-red color, which occurs in small grains imbedded in the manganese ore of the Jakobsberg mines. It is associated with a number of manganese minerals. It contains

If a pure substance, and found to be of constant composition, it may be classed as a massive manganesian variety of brucite. Talktriplite.--This is also a massive substance of yellow or yellowish-red color occurring in grains the size of a pin head at Horrsjöberg. It is transparent, has a hardness of about 5, and contains phosphoric acid, iron, manganese, lime and magnesia, with some fluorine. As it was not separated from its matrix, no analysis of the pure substance was made. It is supposed to be a triplite containing lime and magnesia, but further examination seems to be necessary before classing it among accepted species. It occurs with lazulite, svanbergite and other phosphates.

DIABANTITE-VERMICULITE.-Professor B. K. Emerson describes a diabantite-vermiculite from a dyke of diabase near Turner's

Falls, Connecticut. The foliated chlorite known as diabantite frequently decomposes and then contains amygdules filled with a bronze-yellow substance which exfoliates largely before the blowpipe. The diabantite itself is regarded as an original product of the decomposition of the trap while still hot, while the so-called diabantite-vermiculite is of much more recent origin, being due to atmospheric alteration.

SALT WATER IN SULPHUR CRYSTALS.-Many of the flat crystals of sulphur from Catania, Sicily, contain enclosures of a colorless transparent liquid, in which gaseous bubbles may frequently be seen. Microscopic tubular cavities also traverse the flat laminæ of the crystalline masses of sulphur. Sylvestri finds the enclosed liquid to be a weak aqueous solution of sodium chloride and sulphate, with traces of potassium, calcium, barium and strontium chlorides. The total saline matter amounted to slightly over one per cent.

THE DISPERSION OF CHROMATE OF SODA.-M. Wyrouboff has shown that crystals of chromate of soda having four per cent. of water have very remarkable optical properties. When examined with converging polarized light a plate of this salt shows a curious system of curves very differently arranged on either side of the bissectrix. In the last number of the Bulletin of the Mineralogical Society of France, colored plates are given illustrating the irregular figures produced by polarized light. The irregularity of the curves is due to inclined dispersion combined with considerable difference in the position of the planes of the axes for different colors. It is a very striking example of inclined dispersion, no other substance being known to possess it to such a degree.

ALUMINIUM AS A BLOWPIPE SUPPORT.-The use of a plate of aluminium as a support for the assay in blowpipe operations, as advocated by Col. W. A. Ross, appears to possess a number of advantages over the usual block of charcoal.

The black sublimates formed by arsenic, antimony, lead, etc., invisible upon charcoal, can be distinguished upon the new support. Any sublimates formed can be scraped off in a pure condition for further examination, whereas upon charcoal there is always an admixture of ash. The danger of loss of the sublimate or assay, either by cracking of the charcoal, by blowing away, by admixture with white ash, or by re-sublimation on the incandescent charcoal, is greatly lessened by the use of aluminium as a support, and more minute quantities of a substance may thus be detected. In practice, it is often necessary to place a small slip of charcoal between the assay and the aluminium plate, in order to obtain a sublimate.

The superior heat conduction of aluminium prevents it from combining with fusible metals, as is the case with platinum. For