these rocks as a whole, it is possible that they can be divided into more than one species. As the analyses stand, the rock is composed of iron, either native or combined, with or without varying amounts of nickel, cobalt, tin, copper, sulphur, titanum, phosphorus, silica, graphite, etc. The specific gravity is high. The presence of graphite shows that it is not of organic origin in this case.

Many of the so-called meteoric irons are probably of terrestrial origin, and their environment ought to be carefully studied. The Wiedmanstattien figures are in some measure paralleled by the leucoxene and cleavage structure of titaniferous and magnetic iron in diabases, etc.

The name 'siderolite' was formerly given by Maskelyne to the species to which G. Rose had previously given the name 'pallasite'; hence, since the latter has the prior right, it is hoped that Maskelyne will allow the transference of the termsiderolite' as his own, to this species, to which it most properly belongs, since its individuals are emphatically rocks of iron.

2. Pallasite. This species is formed from a series of rocks of like origin to the preceding; and the structure is that of a sponge- or semisponge-like mass of iron, either native or secondary, holding silicates. The iron has the associations usual in siderolite; and this association holds good wherever the iron occurs in meteorites, and probably on more careful study will be found to hold good, to a great extent, in terrestrial rocks. The silicates are principally olivine alone, or in association with enstatite and diallage. More rarely feldspar and other silicates occur. There are but two or three complete analyses of the pallasites that can be regarded of value; Joy's [Amer. journ. sc., 1864 (2) xxxvii. 243-248] being the best yet made.

The silica increases in amount. up to some 30%, averaging about 20%, with variable quantities of magnesia, rarely exceeding 24% while the remaining constituents are chiefly iron and its associates. Specific gravity less than in the siderolites.

Under pallasite are classed the supposed meteorites of Atacama, Bitburg, Brahin, Breitenbach, Krasnojarsk, Potosi, Rittersgrün, Rogue River, Sierra de Chaco, Singhur, and more doubtfully those of Hainholz, Mejiellones, and Lodran. Of terrestrial rocks under the pallasites belong the olivine-magnetite rocks of Cumberland, R.I., and Taberg, Sweden; for which, as a varietal form, I would propose the name cumberlandite'. It is probable that many other pallasites will be

found on careful investigation of the ironbearing rocks. Some schistose rocks (actinolitic) are probably the result of the extreme alteration of the cumberlandite.

The Ainsa and Carlton meteorites from Tucson have a fine sponge structure, and contain numerous olivine (?) grains; but, although they approach the pallasites, they have been classed with the siderolites.

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3. Peridotite.· This term, applied by Rosenbusch to the pre-tertiary terrestrial olivine rocks, I would extend to all terrestrial rocks and meteorites of a similar composition, — including every thing from the pallasites to the basalts. These rocks are composed principally of silicates and iron; the former preponderating, and the latter sometimes wanting. The silicates are principally olivine, enstatite, and diallage or augite, and sometimes feldspar. The iron is either native, or in the form of pyrrhotite, magnetite, chromite, etc. Silica and magnesia are more abundant, as a rule, than in the pallasites, and less so than in the basalts, while the iron is less than in the former. The specific gravity is also intermediate between the two above-mentioned species.

If it is desired, similar varieties can be pointed out in the meteoric peridotites as in the terrestrial forms; as, for instance, dunite (Chassigny), olivine-enstatite rock (Iowa Co., Knyahinya, Gopalpur, Lancé, Tourinnes, Waconda, Goalpara), lherzolite (Pultusk, Estherville, New Concord, etc.). Also, if desired, an olivine-enstatite-augite division can be made (Tieschitz, Hungen, Grosnaja, etc.).

While part of the meteoric peridotites are entirely crystalline, e.g., Estherville, the great majority are not so, but chondritic in structure. The chondritic structure I believe to be caused by the rapid solidification and arrested crystallization of the masses composed of minerals naturally taking a more or less rounded form; and not from mechanical action, as has generally been claimed. These chondrae show, as a rule, a light or dark gray finely fibrous or fibrous-granular base and semi-base, answering to the globulitic base of the basalts or the felty base of the andesites. This base has heretofore been described as a flocculent opaque-white material, a cloudy substance, the comminuted material, the feldspathic material, Sometimes it is isotropic; but more commonly it affects polarized light according to the amount of olivine or enstatite granules formed in it. When crystallization goes far enough, these granules form by their union the enstatite and olivine grains and crystals.

etc.

The base united with the olivine or enstatite gives the structures which have been taken by Drs. Hahn and Weinland as of organic origin. I should expect to find the chondritic structure in terrestrial peridotites, if any can be found in which the crystallization had been arrested and subsequent alteration has not taken place.

The difference in structure between the rapidly solidified, or chondritic, and the crystalline peridotites is not any greater than that between the tachylitic, basaltic, doleritic, or diabasic state of the basalts.

All serpentines not veinstones, which have been carefully studied, appear to belong to peridotite, as a variety produced by alteration.

4. Basalt. - To the basalts I should assign such meteorites as those of Jonzac, Stannern, Constantinople, Petersburg, Juvenas, Shergotty, Charkow, Frankfort, Shalka, Massing, Busti, Manegaum, Ibbenbüren, etc., so far as their characters are at present known. These have a lower specific gravity than the preceding, a higher percentage of silica, less iron and magnesia, but more lime, and usually more aluminia.

Some of these meteorites, like the Shergotty and Manegaum ones, are apparently allied to the gabbro variety of basalt.

Beyond the basalts are a few imperfectly investigated forms, which, in the majority of cases, are regarded as doubtful meteorites, which appear to belong to the trachytes and rhyolites, but which require to be studied microscopically before definite statements can be made. Of these forms are some described by Shepard, Silliman, and Grewingk. The carbonaceous meteorites have been too little studied to be given a definite position yet; but, excepting the carbonaceous matter, they chemically appear to belong to the peridotites, although it is not improbable that they belong to a distinct species.

So far as studied, I would class the meteorites, the original and eruptive rocks, under the following species: 1°, siderolite; 2°, pallasite; 3°, peridotite; 4°, basalt; 5°, andesite; 6°, trachyte; 7°, rhyolite; 8°, jaspilite.

If further study shows that other species are needed, then the signification of any of the groups from which the new species are taken can easily be narrowed. As many varietal names can be employed under each species as the needs of the science may demand; but they should be as few as possible, and should hold the same relation to the species that the

varietal names of quartz hold to the mineralogical species quartz.

This classification is intended to indicate the probable arrangement of materials in the earth from the interior outwards, beneath the sedimentary formations, as well as to connect, as far as possible, the sedimentary rocks with those from which they were derived.

Meteorites show, to my mind, characters indicating that they have been derived from a hot, liquid mass, and not from any gaseous or solid body, so far as concerns the portion they come from. Of all suggested sources, the most probable one is the sun, provided the eruptive activity now observed on his surface is sufficient to hurl such materials into space; if not now, in past times, when such action was more powerful; or else bodies of similar nature. Meteorites, as far as I have studied them, show no fragmental or tufaceous character beyond such as would be formed by hot, plastic drops falling into a liquid mass of the same material.

They also show that they have not been formed in a locality where life could have existed; for, in that case, the readily alterable materials of which they were composed would have suffered change. M. E. WADSWORTH.

MOLLUSKS OF THE FAMILY
COCCULINIDAE.

EXAMINATION of specimens of a Cocculina or an allied genus of that family, from the north Atlantic, shows some remarkable features. These mollusks, recently discovered by the U. S. fish-commission in the deep sea, are most nearly related to the keyhole limpets (Fissurellidae). The specimens obtained by Prof. Verrill, and examined by me, were, however, all females. A number of specimens, of another species, sent me by Dr. Jeffreys for examination, contained individuals of both sexes; and the males were found to possess a verge, permanently exserted from the inner side of the right tentacle. This is a feature hitherto entirely unknown in the order to which they belong, none of the littoral forms of any of the families possessing any such organ; though, like other limpets, dioecious. It is of course probable that the species of Cocculina found by the fish-commission and Prof. A. Agassiz agree in this character with the form from the north Atlantic, about to be described by Dr. Jeffreys; but the latter shows other differences which may require it to be subgenerically separated from Cocculina proper, though evidently a member of the same family. Wм. H. DALL.

the preseNT CONDITION OF

EXPLORATION.

THOSE readers who wish to follow the reports and news of explorations in distant lands may find some assistance in the following condensed statement concerning the more important recent expeditions in the uncivilized parts of the world. We here note those travellers who have lately completed their field-work, and returned home, and whose narratives are recently published or still awaited; those who are still in the field, from whom occasional reports are received, often only after a time of trying silence; and those who are now planning to enter new ground.

Arctic regions. The situation of parties in the arctic regions at the beginning of 1883 is about as follows, as far as known. Of the Jeannette expedition, the remainder of the original party were about to begin the homeward journey, together with ensign Hunt of the Rodgers. At last accounts they were en route from Irkutsk to Orenburg. Messrs. Harber and Schutze of the navy were expected at Irkutsk, in April, with the remains of DeLong and his party, intending to start for home as soon as the caskets arrived. A bill has been introduced into Congress to pension Mrs. DeLong; and another to indemnify those who lost personal effects on the arctic expedition of the Rodgers, and to reward the friendly natives who preserved the lives of the party during the winter after the burning of the ship. Mr. Leigh Smith of the Eira expedition has presented the Geographical society of London with £1,000, in recognition of its interest in arctic work. The arctic exploring vessel Dimfna, commanded by Lieut. Hovgaard of Nordenskiöld's party, bound for Cape Cheliuskin or Franz Josef Land, was beset in the Kara Sea, near Kara Strait, in the latter part of August. Several propositions have been made to organize an expedition for the purpose of communicating with her and with the Dutch international meteorological party on the Varna, also impeded by ice in the same vicinity. As nearly as can be judged from rather confused telegrams which have been received, no relief-party has actually been organized; though correspondence between the Danish and Dutch authorities has taken place, and the Danish captain Normann has visited St. Petersburg on that business. It has been reported that Larssen, one of the Jeannette survivors, had been engaged to make the attempt; and the last news appears to be, that nomads from the Petschora river-mouth report

that the vessel was in good order, and had arrived from the coast of Novaia Zemlia to remain for the winter.

The situation at the international polar stations for simultaneous meteorological and magnetic observations was favorable when last heard from, except in the case of the Novaia Zemlia parties. The American station at Lady Franklin Bay, the most northern and the first-established of all, has not been communicated with, owing to ice in the northern part of Smith Sound; but, being fully provisioned and equipped for three years, the party are believed to be in good condition. The German station at Kingava, Cumberland Inlet, was successfully established in the autumn of 1882, under Dr. William Giese. Observations are in progress at Godhaab, in West Greenland, under Lieut. Paulsen's direction. Dr. Snellen in the Varna, with the Dutch expedition which aimed at reaching Dickson Haven, near the mouth of the Yenisei, reported beset in the Kara Sea, near Kara Strait, in the last week in August, will doubtless have established a station on the land of Novaia Zemlia if not released by the end of the season. With or near them was the Danish arctic expedition, on the steamer Dimfna, commanded by Lieut. Andreas Hovgaard, mentioned above. The Austrian expedition, commanded by Lieut. E. v. Wohlgemuth, succeeded in establishing its station by Aug. 15, on the island of Jan Mayen, in a ravine on the southern slope of the Vogelberg, named Wilczek valley, after the promoter of the expedition. The latest data from the Russian expedition to make a station at the mouth of the Lena was, that all was progressing favorably, and that the party, under the command of Lieut. Juergens, had reached its destination. Of the subsidiary station, projected by the imperial geographical society at Moller Bay, under the direction of Lieut. Andréieff, no positive news has been received here; but it is asserted that they had reached and would winter in Novaia Zemlia. The Finnish station on the shores of the White Sea began operations Aug. 15. Mahlenberg, with. the Swedish expedition, were safely established at Wyde Bay, Spitzbergen; while the observations of Steen, at Bosekop, near the North Cape of Norway, have been going on quietly for some time. Capt. Dawson with his party were well on their way toward Fort Rae, in the Hudson Bay territory, when last heard from. The exact locality finally decided upon by the Anglo-Canadian party is not yet known. The U. S. party at U'gla-ámi, near Point Barrow, Alaska, were visited and recruited during the

summer, and the first year's observations are already in the computer's hands; while the simultaneous observations by self-registering instruments under the direction of Mr. Marcus Baker of the U. S. coast-survey, at Los Angeles, Cal., are progressing favorably, and will be steadily maintained. Of the proposed subordinate stations at York Factory and in Labrador, no recent information is at hand, though Dr. Koch, charged with organizing the latter, is stated to have reached Labrador in August.

In the antarctic, parties are believed to be already at work on South Georgia and the Falkland Islands; but details in regard to these stations are not yet received. The French station at Orange Bay, Tierra del Fuego, made a successful beginning of operations Sept. 6.

Alaska. Little was doing in Alaska at latest advices. A prospector named Bennett, with a small well-armed party provisioned for fifteen months, had entered the valley of the Atna or Copper river to search for minerals. Edward Schieffelin, with his party and steamlaunch, reached the junction of the Yukon and Tananah rivers during the summer, and were reported in good condition and spirits, intending to ascend the Tananah and search for gold. After the ordinary means of communication were closed for the season, it appears that discoveries of such importance were made that it justified the expedition of a special courier overland to carry the news to others interested in the venture. The route and details of the journey are not stated; but a letter, apparently authentic, and stated to have been so sent, has been published in the Californian papers, indicating that they had found very rich placers.

The U. S. coast-survey steamer Hassler has arrived in San Francisco, after six months' work in Alaska, having made important surveys, and is expected to return to the field in April. Valuable collections were made for the national museum during the voyage. Miners whose movements are not made public are pushing private explorations in many parts of the territory. From the small mining-camp of Juneau, the express companies note the receipt of $240,000 in gold-dust in 1882, against $13,000 in 1881. Capital, which alone can test the permanent value of these discoveries, patiently waits for the long-deferred extension of law and authority over the country by Congress.

South America. The interior of British Guiana has lately been visited by H. Whitely, who passed near the celebrated mountain Roraima; and by M. McTurk, who travelled up the Cuyuní river toward the Venezuelan fron

tier. In the valley of the Amazon, R. Payer, brother of the Arctic explorer, was last reported on the Rio Negro, aiming for the Orinoco. J. B. Minchin has executed surveys of the Andean tableland south of Lake Titicaca for the Bolivian government, of which some account has been published; and J. Ball has followed Whymper in visiting the Andes for mountaineering. Dr. Crevaux, who left Buenos Aires Nov. 20, 1881, to ascend the Rio Pilcomayo, was killed there by the Indians in April of last year; but little has been learned of his expedition, and Fontana left Buenos Aires July 4, to search for the remains of the unfortunate party. It is reported that Lieut.. Guierre, of the French marine, has undertaken a similar expedition. R. Lista, already successful in Patagonian exploration, is engaged on a journey from Bahia Blanca westward to the Andes, thence southward to Punta Arenas on the Straits of Magellan; and a government commission is occupied with the survey of northern Patagonia, to parcel the land for sale to colonists. Lieut. Bove of the Italian antarctic expedition was wrecked on Tierra del Fuego May 31; his vessel was lost, but the members of the party were rescued by an English vessel. The German south polar expedition was safely left on South Georgia Sept. 3: and the French expedition arrived at Tierra del Fuego on Sept. 6. The several astronomical parties sent to southern South America to observe the transit of Venus will probably return with new geographic observations as well; Steinmann, of one of the German parties, intends making an extended tour through Chili and Bolivia before coming back.

Asia. — The Russians continue an active exploration of their vast dominions. Besides extended surveys in the better-known parts of their country, Elisseieff has been examining Russian Lapland, Ivanitzky has been sent to the Petchora, Malakoff to the Ural, and Walter to Eastern Russia; Poliakoff has recently returned from the island Sakhalin, and Regel is still in the Pamir; surveys are carried on in Caucasia, and along the Persian boundary, where Lessar's recent studies have received much attention. It is proposed to send Preievalski, who has so successfully penetrated central Asia, back to the Tian Shan in March, to study its reported volcanic districts. Capus and Bonvalot, leaders of a French scientific party, have returned from Bokhara; and O'Donovan, an English correspondent, has come safely out of Merv with an interesting experience. Exploration in Asia Minor is largely archeological, and engages Humann,

Hirschfeldt, Fester, and Puchstein, who are aided by funds from Berlin, and Clarke, of our own Assos expedition; and parties from Vienna and from England will probably soon take the field, the latter under Conder to be fitted out by the British association for a survey of eastern Palestine. S. Langer, a young German, who had for some time been studying Arabic in preparation for an inland journey, was killed in southern Arabia last June.

Colquhoun and Wahab have safely finished a journey across country from Canton to Rangoon, where they arrived last July; the latter unhappily died on his way to England. The French are sending many parties into IndoChina, a field that few other nations attempt; Garanger has gone to upper Burma; Villeroi d'Augis has returned from Tonquin, but his companion, Courtin, died in the interior; Harmand has entered Siam; Néis, Aymonnier, Septans and Mondon, and Gautier, have gone to Cambodia and Cochin China, the latter expecting to make an extended journey. C. Bock, known for his travels in Borneo, returned to Bangkok from a trip in upper Siam last June. Riebeck had a successful ethnological tour in northern India, and has gone to Batavia; he will return to Europe by way of this country.

Africa receives the lion's share of modern exploration, and largely with a view to commercial advantage. The French continue their energetic work in Senegambia. Col. BerguisDesbordes, who was last year in command of a French government party on the upper Senegal, is to return with a strong force to the country between the Senegal and the Niger. A large railway corps under Jacquier will follow him. Dr. Bayol left Bordeaux last October for the Futa-Djallon highlands, and Caquereau was recently preparing a scientific and commercial expedition for the same region. Capt. Burton and commander Cameron returned last summer from the Gold Coast, where they had been to look into the chances of mining. A Russian expedition under Rogozinski, and an Italian under Bianchi and Licata, have been planned to enter the country at the Bight of Biafra. The latter will be absent several years, intending to cross the continent, passing through the unknown region between the Kongo, the Benue, and Lake Tchad, and finally reaching Abyssinia. No full report has yet been made on a similar long journey, but in the opposite direction, by Matteucci and Massari, on the return from which the former unfortunately died in London, August, 1881. Savorgnan de Brazza and Stanley have re

turned from their expeditions on the lower Kongo; Brazza reaching Europe last June, and Stanley in October. They have unhappily come back with little good-will for each other; and it would seem from the reports of their journeys, so far as yet published, that Brazza has been over-ambitious in his designs. Both are to return for further exploration. In addition to the trading-stations planted on the lower Kongo, several missions have established themselves there, and will probably contribute to our knowledge of the geography of the region. Bentley, Comber, and Grenfell, of the Baptist missionary society, have reached Manyanga and Stanley Pool; Clarke, Richards, Ingham, and Sims, of the Livingston (Kongo) mission, are established at Stanley Pool, and have two small steamboats for journeys up the river; L. Petit, a naturalist who has been along the Loango coast, is going up the Kongo; and Cambier, of the International African association, left Zanzibar last May, with two hundred men, for the Kongo via the Cape.

From the Egyptian Sudan, Emin-Bey and Lupton - Bey report on their explorations. Among the Italian explorers are Cecchi, lately returned from southern Abyssinia; Count Antonelli, who was to begin his work at the Italian colony Assab, on the Red Sea; P. Sacconi, to establish a trading-station at Harar, southwest of the head of the Gulf of Aden; and Capt. Casati, whom Dr. Junker has met on the Uelle. The latter is still in this little-known region, attempting to solve the problem of its drainage. The German African association at present has several exploring parties at work: Flegel, aiming at Adamaua, with hope of reaching the unknown country beyond between the Benue, Shari, and Kongo; Pogge and Wissmann, who entered from the west coast, and reached the upper waters of the Kongo, where they parted, · - Pogge to return westward, and Wissmann to go on eastward to Zanzibar, where he safely arrived last November; and Stecker, who had been with Rohlfs in Abyssinia about Lake Tana, and who then attempted to go southward through the Galla lands to the coast. There is also a German expedition under Böhm, Kaiser, and Reichard, at Kakoma in Ugunda, and a Belgian station at Karema, where Storms has gone to relieve Becker; Dr. G. A. Fischer was to enter eastern Africa from Pangani last November, with an expedition fitted out by the Hamburg geographical society; he hopes to reach Victoria Nyanza, and then turn northward. The appropriation of 100,000 marks by the German Reichstag for African exploration is recently