Hall effect. - Dr. E. H. Hall finds that the values of the rotational coefficients' given by him at the York meeting of the British association for zinc, aluminum, copper, brass, and lead, are confirmed by later experiments. On trying the effect of change of temperature, only a negative result was obtained with gold; with iron, the increase was two-thirds of one per cent, with a rise of 1° C. The coefficient, with change in the strength of the field from 1,000 to 7,500 absolute units, seemed to increase; but, of this, Dr. Hall does not feel sufficient confidence to publish his results. The object of another experiment was to determine whether any part of the rotational effect could be made permanent. For this purpose, a thin piece of very hard steel spring was used as the plate. The direction of the equipotential lines was permanently changed by the action of the magnet. This change was in the same direction as the temporary effect due to the magnet's action, and perhaps equal to two per cent of this. (Amer. journ. sc., xxv. 215.) [1018

ENGINEERING.

The power of a steamship. - The Oregon, of the Guion line, is to be the most powerful and the fastest of the transatlantic passenger-steamers. Her displacement is about 11,000 tons. Her engines have three cylinders, and are of 13,000-horse power. The boilers contain 74 furnaces, consume about 300 tons of coal per day, evaporate 2,700 tons of water, require 6,000 tons of air to support the combustion, or a volume of nearly 175.000,000 cubic feet, and the power developed is sufficient to raise about 200,000 tons one foot high per minute. The ship will make 20 nautical miles (knots) per hour, against an estimated resistance of 94 tons, or twenty times the resistance overcome by the most powerful locomotive. The Atlantic will be crossed in six days in good weather. (Lond. engineer, April.) R. H. T. [1019

The exhaust-steam injector.- Mr. L. J. Groves read a paper before the Institution of engineers and shipbuilders in Scotland, March 20, describing the exhaust-steam injector. It resembles the feed-water injector of Henri Giffard both in principle and in its general construction. It forces the feed-water into the boiler by the action of the exhaust-steam at nearly atmospheric pressure, at the same time heating considerably the water passing through the instrument. It differs from the usual forms of Giffard injector in having the mixing' or 'combining' nozzle split in such a manner that it lies open when the apparatus is not working, but closes up to form the standard form of nozzle when the instrument starts into operation. The steam-nozzle is much larger than that of the common instrument, and has a central spindle, of cone shape, to direct and concentrate the jet. The instrument starts automatically when the engine starts. It draws cold water, and forces it into a high-pressure boiler at a temperature of 190° F. (88° C.). On a locomotive it has forced feed-water into the boiler at a temperature of 277° F. (136° C.), against a steam pressure of ten atmospheres.-(Trans. inst. eng. shipb. Scotland, April.) B. H. T.

[1020

2CO,+ NH,CH + 2NHg + CgH,NO, + CH,O.

By oxidation with nitric acid, theobromine gave methylparabanic acid and methylamine, and caffeine gave dimethylparabanic acid and methylamine. In the preparation of theobromine from cacao, Schmidt found in the mother-liquors needle-shaped crystals which proved to be caffeine. The action of hydrochloric acid upon xanthine is shown by the equation,

CH_N,O, + 6 HgO = 2CO,+3NH,+C,HNO, + CH,O,. — (Ann. chem., ccxvii. 270.) C. F. M.

[1021

A new refining process. —At a recent meeting of the Société de l'industrie minérale, M. Thiollier communicated the details of a method of refining pig, and finished iron and steel, by the action of damp hydrogen. To assure himself that the well-known laboratory experiment may be carried out on a large scale, he has erected experimental works near Paris, having four furnaces with cast-iron retorts capable of treating about one ton at a time. The retorts are coated inside and out with a vitrifiable substance to prevent oxidation, and loss of gas through the pores of the metal. Hydrogen is introduced through small metal tubes; and, in order to prevent all danger of explosion, the air in the retort is displaced by carbonicacid gas before the hydrogen is allowed to enter. After being annealed for a few hours in an atmosphere of hydrogen at a dark-red to cherry-red heat, malleable cast iron acquires all the properties of steel. Coarse steels may be changed into fine tool steel. On wrought iron the action is slower. The cost is esti

-

mated at two francs per 100 kilos of poor-quality iron. (Iron, April 6; Eng. min. journ., March 31.) R. H. R. [1023 The working of blast-furnaces. At a meeting of the Society of mechanical engineers, Jan. 25, Mr. Charles Cochrane read an elaborate paper on the working of blast-furnaces with special reference to the conditions under which the analysis of the escaping gases is of value. The object of the author is to establish the fact that all economy in fuel, consumed to make a ton of pig iron with any particular class or size of furnace, is governed by three conditions: 1. Temperature of air introduced; 2. Temperature of escaping gases; 3. The quantity of carbon which can be maintained in the condition of carbonic-acid gas after it has once been transformed to this degree of oxidation from the carbonic oxide produced in the hearth. The paper contains tables calculated for conditions varying from good to bad. Several illustrations of furnace-working are given, of which the No. 3 Ormsby furnace is one. The ratio of carbonic acid to carbonic oxide was 424. The temperature of the blast was 700° C.; of the escaping gases, 340° C. Carbon as coke, per ton of pig, was 21.98 cwt.; carbon in limestone flux, per ton of pig, was 1.50 cwt. By the tables it is shown, that, without the weight of carbon as a factor, there are six conditions of furnace-working indicated by the analysis of the gases; but, taking the carbon also into account, it is shown that the ideal furnace should have used but 16 cwt. of carbon per ton of pig: hence 5.98 cwt. of carbon have been reduced from carbonic acid to carbonic oxide. — (Iron, Feb. 2.) R. H. B. [1024

are

The Carvés coking system. The ovens long, high, narrow chambers of brick-work built side by side. The partition-walls contain horizontal flues as well as the floor of the ovens. No air is allowed to enter; and the only opening left during the heating is the pipe which carries the volatile products through condensation and absorption apparatus in order to save the tar and ammonia-water. The gas is conducted by the floor-flues to the small fire-grate at one end of the oven, and there burned; the products of combustion pass through the wall-flues, on their way to the stack; and, by this means, much heat is saved. There is no burning and consequent loss of the coal itself, as is the case in the beehive ovens; also the valuable by-products are saved. Tests show that the hardness of the coke increases as the width of the oven decreases. The cause of this is probably due to the quick and intense heating. The fixed carbon obtained in this way is about 75 per cent, while other methods give only 55 to 65 per cent. A battery of one hundred ovens will furnish steam for about 400 horse-power over and above the making of the coke and the rendering of the products. (Coal, March 28.) R. H. R. [1025

Artificial fuel. The process of Mr. E. F. Loiseau for making artificial fuel from coal-dust is in successful operation in Philadelphia, where from 80 to 300 tons, according to size of the lumps, are made daily. The process of manufacture may be briefly outlined as follows:

The coal-dust is fed into hoppers, together with about eight per cent of bituminous slack, from which it passes through a series of four cylindrical revolving drums, in which it is thoroughly dried. From these it is carried to a receptacle situated near the press. The dust, still at a temperature of about 140° F., is then thrown into the mixing apparatus, in which it is thoroughly stirred by revolving shafts with blades, while the proper quantity of pitch and

coal-tar is added from a reservoir in which it is maintained at a temperature of 180° by steam-heat. The pitch is mixed with a certain quantity of coal-tar to give it the proper toughness. When thoroughly mixed with the melted pitch, the mass is plastic, and can readily be moulded into any desired shape. It is then carried to the press, where it is delivered between rolls having moulds upon their surfaces, from which the egg-shaped lumps are discharged. When discharged from the press, the lumps are quite hot, and have to be cooled by jets of water.

As thus prepared, the fuel is compact and very hard. Formerly clay was used as a cementing material, but now no incombustible or ash-producing material is required. The fuel is said to be even superior to the natural coal; and this opinion is borne out by an analysis which gave the following results:

Carbon Hydrogen Moisture.

Ash

Earth-worms and fertility. — According to Hensen, earth-worms increase the fertility of the soil by forming burrows through which the roots of plants can descend into the subsoil. This applies chiefly to Lumbricus terrestris, while L. communis is confined chiefly or entirely to the surface-soil. The tap-roots of many plants, he thinks, may be able to force their own way through the hard subsoil; but the more slender side-roots descend chiefly through worm-burrows, or other channels, such as those left by old decayed roots. By excavating in frozen ground, he was able to trace roots downward through worm-burrows, and to observe that the layer of excrements with which the latter were lined was covered with a delicate network of root-hairs proceeding from the root in the interior. An important function of these roots Hensen believes to be, to supply the plant with water from the moist subsoil; and this is particularly important in the case of quick-growing annuals, like the cereals, which must develop their root-system rapidly, and frequently have to withstand prolonged dry weather. It is plain that no new material can be added to the soil by earth-worms; but they effect the fixation of vegetable matters in the soil by drawing into their burrows leaves, and other loose fragments of vegetation: they hasten their decomposition, and distribute them through the various layers of the soil. - (Landw. jahrb., xi. 661.) (1027

H. P. A.

Archeological lithology. - Jannettaz and Michel from chemical and microscopic examination of two fragments of images obtained in Oaxaca, conclude that the rock is serpentine. Like examination of a pierced cylindrical bâton from Tetihuacan caused it to be regarded as a microcrystalline albite. The rocks were respectively colored greenish gray, deep green, and milk-white with a greenish tinge. (Bull. soc. min. France, April, 1883.) M. E. W. [1029

Meteorites.

Fusion structures in meteorites. -The reviewer having expressed himself favorably (24) regarding an abstract of Wiechmann's paper, it becomes necessary, on examination of the completed form just published, to withdraw his commendation. The paper is a rambling, nearly worthless essay. So far as we can judge, the conclusions appear to be in the main correct; but they are mere guesses so far as this paper goes. The plates are coarse and unnatural. The only real evidence the article contains (which can be found on almost every page) shows the author to be destitute of the elements of the knowledge necessary for the work he has undertaken. — (Ann. N. Y. acad. sc., ii. 289.) M. E. W. [1030

MINERALOGY.

Pachnolite and thomsenolite-Since the analyses of J. Brandl have shown these very similar minerals to have the compositions (Al F3, Ca F2, Na F) and (Al F3, Ca F2, Na F, H2O) respectively, Des Cloizeaux has subjected the same to renewed optical and crystallographic examination. The crystals of pachnolite are always very small, and associated intimately with the thomsenolite. When heated in the closed tube, they decrepitate violently, giving no water. They are referred to the monoclinic system, with axial relation cb: a = 1.326676: 1:0.859495 ß = 89° 41'. The thomsenolite is distinguished by its perfect basal cleavage. When heated in the closed tube it decrepitates violently, giving off acid water. The crystals are monoclinic, with the faces of the hemi-octahedron and prism striated parallel to their intersection with the base, and having the axial relation cb: a = 1.0883: 1: 0.998741 B = 89° 12′.

These two minerals, which have been much confounded and united, are thus shown to be distinct, not alone in chemical, but also in physical and crystallographic properties. (Bull. soc. min., v. 317.) [1031

8. L. P.

PHYSICAL GEOGRAPHY.

Ripple-marks. The cause of the production of ripple-marks in marine sands, lately investigated by A. R. Hunt (Proc. roy. soc., xxxiv. 1882, 1), has been further studied by C. de Candolle. He shows that they are caused by a horizontal oscillating or intermittent motion of the bottom-water, generally arising from the effect of wind on the surface, and makes it probable that they are produced at very considerable depths, and in directions independent of the surfacewinds blowing. Such ripples are always formed on the surface of a viscous mass when a liquid moves back and forth, or intermittently forward, over it. Attention is called to the possibility that rippled cirrus clouds may have a similar origin, and to the resemblance between some artificial ripples and certain organic forms. Several well executed plates illustrate the paper. (Arch. sc. phys. nat., ix. 1883, 241.) W. M. D. [1032

Patagonia.-C. Martin calls attention to the contrast, dependent on the winds and consequent rain, between the country east and west of the

southern Andes. North of lat. 40° S., where even the passes approach the height of Mont Blanc, this contrast is strongly marked; but farther south the cordillera is broken, and gives more open passage to the moist winds. At its eastern foot the numerous and large lakes are all fresh, having overflow during at least part of the year. Farther eastward the country becomes dry and barren, though nowhere being a desert of drifting sand. Its small lakes are saline. The Patagonian Andes, therefore, do not constitute a continuous range, but consist of a series of moderately high volcanoes on the ragged western border of the tableland, deeply cut by fiords and by rivers, that in some cases rise at a considerable distance from the Pacific coast, as found by the explorers, Cox, Fonck, and Musters. Forests extend as far north as lat. 35° S., but there they are found only on the mountain spurs. South of lat. 37° the lowlands also are forest covered, except where occasionally cleared by the Indians, who have, till lately, occupied this district to the exclusion of Spaniards and Chilians, and again between Valdivia and Osorno (lat. 40° to 42° S.), where opened by German colonists. The mainland and archipelago of the fiord region, where the Chilian hydrographer, Simpson, has counted over one thousand islands, are well wooded, the trees extending above the foot of the glaciers, up toward the snow-line. A brief description is given of the more important forest-trees. A peculiar building of lake-barriers is described (whether on sufficient observation or not does not appear) at several points in the southern fiords; for example, in the bay into which the glacier from the flank of San Valentino (3,870 met.) gives off its bergs, which, on melting, form a bar like a moraine, and in time enclose a part of the bay, which then becomes fresh by outward drainage. One such lake has already been formed here, and another is forming. — (Mitth. erdk. Halle, 1882, 88.) W. M. D.

GEOGRAPHY. (Europe.)

[1033

Be

Surface and structure of Wurtemberg. ginning with a quotation from Murchison, - "No really good topography can be made by any surveyor who neglects geological data," E. Hammer describes the close relation between the geological structure of Wurtemberg and the form of its eroded surface. Valleys cut in the buntsandstein have evenly rounded side-slopes; in the muschelkalk the slope begins abruptly at the line of a hard upper stratum, and sinks directly to the base; in the keuper the slope is broken by steps or terraces of harder and softer layers. Most of the larger streams follow the muschelkalk, and their upper courses meander so irregularly that the most ordinary topographic map reveals its presence. The forms of the successive lias, Jura, and tertiary deposits are given in detail. In upper Swabia, glacial deposits present their peculiar landscape of systemless hills and hollows, with drainage so imperfectly established that peat-swamps occupy a considerable part of the surface. The lack of illustrations decreases the value of this paper; but its method is excellent, and should find many followers. ― (Kettler's zeitschr. wiss. geogr., iii. 93, 148.) [1034

W. M. D.

Area of Italy. - The official estimates of the area of Italy give a surface of 296,323 □ kil., according to figures established in 1864; but in the past. year several statistical almanacs have changed this to 288,540 kil., according to the results of Gen. Strelbitsky (Superficie de l'Europe, 1882). Prof. G. Marinelli of the university of Padua does not ap

W. M. D.

W. M. D.

prove of this change, as he regards the cartographic material on which the new estimate was made as of less than mediocre value. - (Boll. soc. geogr. ital., vii. 1883, 241. Further discussion of the question is given in Atti istit. venuto, ix. 1883, 179, 295.) [1035 (Asia.) Euphrates valley. -A corrected sketch-map_of M. v. Thielmann's route from Kerbela, near the Euphrates, westward across the desert valley to Palmyra, is prepared by R. Kiepert. It shows the great barrenness of the adjacent flat country, slightly indented by dry stream-courses extending north-easterly to the river. Some of these are two hundred feet below the general surface, and sometimes contain pools and springs. (Zeitschr. f. erdk. Berlin, xvii. 458.) [1036 Improvements in Persia. - Dr. J. E. Polak concludes his account of an expedition to the Karagan and Elvend regions in 1882 by noting the changes in the country since his earlier visit in 1860. In addition to the overland telegraph-line that connects India with Europe, there are several shorter lines across the country. The service is regular, and despatches can be sent in English and French as well as Persian. Many new roads have been constructed, and, although not to be compared with the smooth highways of Europe, they serve well for caravan traffic; but roads are still lacking in many districts. A responsible postal-service is established, both for the interior and for foreign correspondence; and a uniform currency in gold and silver is introduced. With the improved means of communication, letters of credit can now take the place of a heavy supply of metallic money, that travellers formerly found necessary. Railroads are projected from the Caspian southward: they will have the advantage of finding coal and wood near their lines, but also the difficulties of heavy grades between the coast and the interior tableland, and a lack of good harbors at their termini. European methods are introduced in many civil and military arts, and a general tolerance of most sects and nationalities. Whether this improvement will continue or not is doubtful, as the present Shah is over fifty years old, and none of his sons give assurance of carrying on his reforms. (Mitth. geogr. ges. Wien, xxvi. 1883, 106.) W. M. D. [1037

(Pacific Ocean.)

Polynesia. - An entertaining sketch of a threeyears' voyage to many of the island-groups in the western Pacific is given by Dr. O. Finsch, who has lately returned to Europe with large collections. His studies were chiefly ethnological. Opportunity for such investigation is rapidly disappearing; for the local peculiarities of the natives on the various island-groups are fast fading away under the influence of traders and missionaries. Among the natives of the Marshall group, the making of large canoes from the trunks of breadfruit-trees is already a lost art. On one of the Caroline Islands, only about three hundred natives remain; and their earlier customs have largely disappeared with their conversion to christianity. In the Melanesian Islands there has been less change. The natives go naked, and retain their cannibal fashions; and, by the absence of certain peculiarities not at all flattering to our civilization, the lack of European influence is further proved. Herr Finsch found the atolls monotonous. "They are like American hotels: in knowing one, you know them all." The higher islands have much more interest. The irregularity of communication between the different islands makes travel very difficult. One

Philippine Islands. - Dr. S. Kneeland regards this group, with many others south-east of Asia, as the remains of a sunken continent, finding evidence for this view in their broken outline, in the distribution of races and their monuments, and in the numerous volcanoes on the fracture along the border of the lost land; but this latter point is certainly open to question, as is his opinion concerning the finished condition of the earth, and the office of volcanoes as safety-valves to earthquakes. Volcanic and seismic phenomena are very marked on these islands. The symmetrical cone of Mayou gave forth a continuous stream of lava from its very summit for the last five months of 1881, and, in earlier years, has done great damage to the villages on its flanks. The ruins of the old town of Daraga, on the south-east, may still be seen partly covered by the lava of 1814. Majayjay or Banajao, now dormant, formerly contained a lake that was destroyed in the eruption of 1730. Large stones thrown from it are scattered far and wide beyond its lava-flows.' From the lake of Bonbon, seventy miles in circumference, rises the cinder-cone of Taal, twelve hundred feet high, with a ragged crater six miles around, within which is a sulphurous lake giving forth suffocating fumes. The effect of earthquakes is seen in the change from heavy stone to light wooden buildings of Spanish construction. The most violent recent shocks at Manila were in 1863 and 1880. A meteorological observatory in charge of the Jesuits publishes a daily weather bulletin; January and February have the coolest weather, with dry north winds; April and May are hottest; and August and September have the heaviest rains. Having an extent from north to south over several degrees of latitude, and a strongly broken surface, the islands enjoy a remarkable variety of climate, and the pine and maize flourish as well as the palm and orange. The author's chief attention was given to ethnographic questions, and some of his results have already appeared in SCIENCE.-(Bull. Amer. geogr. soc., 1883, no. 2.) W. M. D. 1039

BOTANY.

Flowers of Turneraceae. From studies by Urban, it appears, that, of the eighty-three species, fourteen are certainly homogone, and five probably so, while forty-eight are dimorphic, and eight probably so. Six species are incompletely dimorphic; one has six varieties homogone and six heterogone, and one is unknown, with respect to the length of the essential organs. Mathurina penduliflora, Piriqueta capensis, Berneriana madagascariensis and odorata, which depart most from the other Turneraceae, and are remarkable for their geographical distribution, are homogone. Aside from these, the homogone species are represented in all genera, and in most of the smaller groups of naturally related species, and they are distributed as widely as the order.

When a single individual of a species, found homogone in many specimens from different localities, shows an inclination to heterogony, this manifests itself in the increased length of the style, while the stamens retain their usual length. The northernmost variety of Turnera ulmifolia is represented only by the long-styled form. Certain species are characterized as incompletely dimorphic. The long-styled form is as it should be, while in the short-styled flowers the branches of the stigma nearly or quite reach the anthers. In these self-fertilization can

occur if insect visits fail. These are found only in groups where specific distinctions are not well marked. In completely heterogone species, the differentiation extends only to the relative length of stamens and pistil, or it may include the direction of the short styles, which diverge so much as to bring the stigmas in contact with the perianth, or even the length of the stigmatic rays and the form and pubescence of the style. The colors of the flowers do not stand in any relation with the monomorphism or dimorphism. Dimorphic species have more conspicuous flowers than their nearest homogone relatives, this depending either on the size of the individual flowers or on their grouping in compact clusters. The duration of the several species shows a remarkable connection with the presence or absence of heterogony. The largeflowered, dimorphic species are perennials, while most of the small-flowered, homogone species are annuals. (Berichte deutsch. bot. gesellsch., 1883, heft 2.) W. T.

-

[1040

Floral evolution in monkshood. Grant Allen gives a popular account of the flower of Aconitum, contrasting it with a buttercup, and showing how symmetry and regularity have been lost, and its blue color acquired, through the advantage derived from the visits of bees favored by these changes. The bilateral structure, and the suppression of the lower three petals, are connected with the lateral position of the flowers on the axis of inflorescence; while the reduction in the number of carpels, and the increase in the ovules, secure the production of as much seed from a single visit of a bee as the buttercup secures from numerous visits of the mixed group of insects to which it is open. The differences in the relative position of the essential organs during anthesis would also have proved very interesting in this connection. (Knowledge; Pop. sc. monthly, May.) W. T.

[1041

The relation of the tension of the bark to the formation of annual rings in wood. — It is stated in several text-books, that, owing to the slighter pressure exerted by the bark in the spring, wider wood-cells are produced than at a later period, when the pressure is considerably augmented. Experiments by De Vries certainly can be interpreted in this way. Krabbe has recently investigated the subject in a somewhat different manner, and has arrived at a different conclusion. It cannot be said that the subject has yet been settled. It offers a promising field for further work.

Krabbe's method is the following: strips of bark, not as yet covered with cork, are carefully cut from the stem, and the amount of force required to restore them to their original breadth determined exactly by means of weights. It is well known that such strips of bark shrink at once, and that a considerable force is needed to bring them back to their former size. The tangential tension of the bark increases with the growth of the stem up to the time when the corky layer is formed, unless some injury influences the phenomenon. But if we look at the radial pressure (reckoned as the quotient of the tangential tension divided by the radius), it is found that this diminishes with increase of the stem in thickness. Furthermore, the radial pressure in autumn is about that of spring, never differing from it more than one gram in the square millimetre; hence being, as Krabbe thinks, too slight to account for the difference between the spring and autumnal wood. He explains the increase of growth, when pressure is removed by taking off the bark, by the pathological activity following wounds. - (Sitzungsb. akad. wiss. Berl., Dec. 14, 1882.) G. L. G.

[1042

ZOOLOGY.

(General paleontology.)

Jurassic of Galicia. In volume v. of the memoirs of the academy of sciences of Cracovia, Dr. Alth, under the title of the Limestone of Nizniow, and its fossils,' describes the recently discovered and very important beds of that locality. From the character of the fossils he refers them to the upper white Jurassic, answering to the united strata of the Kimmeridge and Portland. This work is important as showing the existence of the Jurassic in eastern Galicia, where it was formerly unknown, and of great paleontological importance as describing 179 species of fossils, of which 124 are new. Of these, 5 are annelids, 93 gastropods, 57 acephalans, 5 brachiopods, 2 echinoderms, 6 corals, 6 rhizopods, and 4 plants. Curiously, only one cephalopod has been found, the Nautilus Geinitzi. (Bull. soc. geol. France, Jan., 1883.) J. B. M. [1043

The sigillarian stumps of Nova Scotia. — One of the most interesting results of the later visits of Sir Charles Lyell to this country was his discovery, in company with Dr. Dawson of Montreal, of a number of animals entombed in stumps of sigillarians in the coal-measures of Nova Scotia. Dr. Dawson has recently renewed his explorations in the field by aid of a grant from the Royal society of London, and his conclusions have just been published. Up to 1876, only three additional trees, of those which became accessible by the wasting of the beds, furnished animal remains. But by cutting and blasting, twenty others have now been examined, ten of them proving productive. Dr. Dawson finds that "the circumstances of the growth and entombment of this forest entirely contradict those theories as to Sigillaria and Stigmaria which suppose that these plants grew in water, or on submerged areas. . . . The surface on which the trees grew... must have been underlain by several feet of peaty matter." The number of terrestrial batrachians found in the stumps has been doubled by these investigations, additional species of Hylonomus and Hylerpeton having been found, and Fritschia and Sparodus added to the genera, besides a new form called Amblyodon, represented imperfectly by a few teeth and bones, - making, in all, seven genera and twelve species. Of land-snails, besides Zonites priscus, and Pupa vetusta, found before, another species of Pupa, called P. Bigsbii, has occurred. Of articulates, S. H. Scudder reports two more (unnamed) species of Archiulus, bringing the number of myriapods to six, and fragments of scorpions not before recognized probably belonging to two species. A half a dozen plates illustrate the batrachian remains. A note is added on the footprints of batrachians observed in carboniferous rocks of Nova Scotia, which are referred to six species, equally divided between Sauropus and Hylopus. (Phil. trans. roy. soc. Lond., 1882, 621.) [1044

Mollusks.

Variations in Unionidae. — Rev. W. C. Hey contributes a suggestive paper on the variations observed by him in Anodonta and Unio in the waters of the Ouse and the Foss, and the canals communicating with them, within a very limited area. The point of it is, that, apparently, very slight changes in the environment produce important changes of appearance in the mollusks referred to; though why such causes should produce such effects is not by any means clear. (Quart. journ. conch., 1882.)

W. H. D.

[1045