are thrown about in the utmost confusion; while between their interstices the most suffocating vapors arise.

Lastly, at the foot of the cone are found two more groups of extinct vents. The total number of active vents is about seventy.

Vapors also find their way through the loose soil, which consists of ashes, sand, and sulphur: their odor was that of burnt sulphur and of rotten eggs; from which it is to be presumed that they consist of a mixture of the sulphurous and hydrosulphuric acids. The authors next mounted with incredible labor to the summit of the volcano, whose crest is serrated with sharp pyramidal rocks, resembling the teeth of a saw. The inner walls near the top consist of detached blocks and rocks of all sizes; and lower down, of sand and soil with occasional patches of vegetation. The rocks blackened by time, the profound obscurity, and the vast columns of smoke issuing from an abyss 2460 feet in depth, are described as forming a majestic and terrible scene.

The authors give the following reasons for believing the eastern crater to be the more ancient. It contains no traces of volcanic fumeroles, and its cone of eruption has entirely disappeared; its interior walls are but slightly inclined; and the ridge which separates the two craters, though gently inclined towards the eastern crater, is cut off almost perpendicularly towards the western. The trachytic rocks of the eastern crater are covered over with sand and pumice, which have evidently been ejected from the western. The eastern crater burst forth near the summit of the ancient Pichincha, and the western on its side.

The later eruptions of Pichincha have produced nothing but pumice, that being the only rock visible at the surface. Below the Arenal, the sides of the mountain are covered with vegetation, the surface being composed of soil, sand, and pumice, without any débris which can be attributed to recent convulsions. The few masses of rock which pierce the vegetable crust are probably part of the interior stony structure. Yet the eruptions which caused the present craters must have been tremendous solid rock which once formed the summit of Pichincha and the matter thrown from the interior must have reached immense distances, while violent earthquakes must have desolated the neighboring country. Had these been witnessed by man, tradition ought to have preserved the memory of them. But according to the historian of Quito, previous to the eruption of 1539, Pichincha was not known to be volcanic; the traditions of the Indians being absolutely silent on the point. The authors think it therefore probable that the eruptions which caused the present craters took place before man inhabited this part of the Cordilleras. The fumeroles of the present cone must also have been obstructed during a great lapse of time; otherwise the Indians must have noticed great columns of smoke, such as now rise from it. The only known eruptions in 1539, 1577, 1587 and 1660, have all issued from the existing cone; and to this epoch must be referred the blowing away of the matter which choked the old vent, and the formation of the present cavities.

But in spite of history and tradition, it is impossible to believe that the vast blocks, more than 12 feet in diameter, which cover part of the plain of Iña Quito, distant 3 leagues, can have been thrown out by the eruption of 1539. There are no traces of such recent eruptions on

the sides of Pichincha, and the present cone is far from being considerable enough to have furnished such a vast quantity of projectiles. Those which were thrown at angles less than 45° would strike against the inner walls of the crater, and roll back again into it; those only which were thrown at greater angles, and with force enough to rise 16,000 feet above the plain of Quito, could reach their present positions; and although this is not physically impossible, yet it is contradicted by the appearances of the later eruptions, which have clearly been of a very tranquil description.

The authors consider as equally fabulous, a tradition that the eruption of 1660 was accompanied by showers of incandescent rocks, which are said to have fallen on all sides, but of which not a vestige is now to be seen.

J. C. M.

5. Count Keyserling's Geology of the Northeastern Extremity of Russia in Europe; by Sir R. I. MURCHISON, (Proc. Brit. Assoc., 1847, Athen., No. 1028.)-Sir R. I. Murchison exhibited the new work, entitled, "Wissenschaftliche Beobachtungen auf einen Reise in das Petschora-land," and explained its value in completing the acquaintance of geologists with the great northeastern angle of Russia in Europe, which is watered by the river Petschora. The geographical and astronomical observations in this expedition (to a region previously known only imperfectly to the Russians through the traders in fur) are by M. P. von Krusenstern, of the Imperial Navy. The geological outline of the present work (executed in 1843) was communicated to Sir R. I. Murchison previous to the publication of the volumes on the "Geology of Russia and the Ural Mountains," and constitutes one of the chapters of that work; but the object of this communication was to call attention to the additions which had appeared: first, in regard to the physical and geological delineation of this wild country in two maps; and, secondly, to the numerous plates (twenty-three in number) of the organic remains of the Silurian, Devonian, Carboniferous, Permian, and Jurassic systems, occurring in a hitherto unexplored region which extends over near 11 degrees of latitude; viz. from 60° to 71° N. lat., and 25° long., including the northernmost range of the Ural Mountains. Sir R. I. Murchison stated that although the eastern flank of that chain had been touched upon at one or two points by the authors, and notably in N. lat. 65°, enough had only just been done by them in this respect to connect, in an approximate manner, the structure of the northern end of the chain with that previously described: all this rocky territory, extending 3 and 4° of latitude beyond the limits of arboreal vegetation, is now under the survey of a distinct expedition, commanded by Col. Hoffman, and sent out under the auspices of the Geographical Society of St. Petersburg. The chief geological interest attached to the work of Count Keyserling, (in addition to the points alluded to,) is the determination of an axis of palæozoic rocks constituting the Timan Ridge, which, branching off from near the Ural Mountains in lat. N. 62, trends in a N.N.W. direction to the left bank of the Petschora to the bay of Techeskaya, and is prolonged into the promontory of Kanin

This work consists of a 4to volume of text, published in German at St. Petersburg in 1846, with 23 elegant 4to plates of fossils, and two maps.-J. D. D.

Nos in lat. 68° 45'. This ridge, divergent from the meridian direction of the Ural Mountains, but parallel to their northern extremity, seems to form a part of the great girdle of palæozoic deposits which wrap round the crystalline nucleus of Lapland and Scandinavia, of which the Baron Leopold von Buch, by his description of the fossils collected there, has recently determined an important fragment of carboniferous age in Bear Island near Spitzbergen, on the north-western flank of Scandinavia.

6. On the Fossil Vegetation of Anthracite Coal.—Mr. J. E. TESCHEMACHER, at the recent meeting of the American Association of Geologists and Naturalists, read a paper on this subject, confining his observations to the remains of vegetation found in the body of the coal, apart from that in the accompanying shales. The principal points of the memoir were that, the remains of the larger forms of the coal epoch, as well as of the smaller plants, were abundant in the coal, contrary to the usual opinion. Specimens were exhibited from the interior of the coal, showing the external and internal parts of plants-the vessels-the leaves the seeds, &c.

Since the meeting, Mr. Teschemacher has continued his investigations, and has communicated in a letter to one of the editors the following results.

1st. What I considered as vessels were said to be mere marks of sliding of the coal. Prof. Bailey prepared a specimen of this, by his method, and told me that if I found vessels there, my proposition was correct. Examined by Agassiz and myself, with his large Oberhauser, it turns out to be nothing but a mass of perforated vessels, as clear and distinct as if they were recent. Mr. Agassiz observed, one moment suffices to remove every doubt on the subject."

66

2nd. What I considered as fossil seeds, were said to be mere peacock-eye coal; the dark carbonaceous centres of these seeds which I held to be carbonized cellular matter, was thought to be a mere mistake and the seeds imaginary. I have since discovered them with distinct and clear apparently spinous appendages. Mr. Agassiz thinks the seed a Samara, and I have found sufficient quantity to pick out the carbonaceous matter from the interior with a fine needle-decarbonize it in a clean platina crucible over a spirit lamp, with every possible precaution to prevent any foreign substance mixing therewith; on examining this with the Oberhauser, 700 diameters, Mr. Agassiz shewed to Dr. Gould and myself the cells as clear and plain as possible; it is a mass of cellular matter as I stated. You may of course imagine the extreme tenuity of the parietes of cells of seeds when decarbonized, and the difficulty of those less experienced than Agassiz in the microscope in managing the subject-he feels quite convinced of their being fossil seeds. The nature of the genus of plants must require further examination.

3rd. The smooth glossy surfaces which I considered the external parts of large plants rendered smooth by intense pressure, were said to be nothing more than slickenslides. My position here is proved much more easily than in the other cases, by specimens passing gradually from the smoother through different degrees of protuberance, (all still smooth and polished,) until we arrive at the full form of the Lepidodendron. Nay more, I have found the parallel lines (channels) which are

on the slickenslides, also on the perfectly formed Lepidodendra. The correctness of my views here I could prove to the most skeptical.

The discoveries still to be made on this subject are numerous and important, and I doubt not that the investigation of the coal itself will soon solve the doubts hitherto existing in the comparison of the coal fossils with recent plants.

I will merely add, that I have found quite distinctly the impression of the cellular cuticle of some of these plants, which of course cannot be seen in an impression on shale, the grains of the sedimentary matter being as large as the surface of the cells; but on the pasty mass of coal the impression is perfect.

III. BOTANY AND ZOOLOGY.

1. Description of a supposed new species of Columba, inhabiting Mexico; by GEORGE A. M'CALL, (Proceed. Acad. Nat. Sci. Philad., July, 1847.)—Columba solitaria.-Length 13 inches 9 lines. Alar extent 23 inches. Wing, from the flexure, 7 inches, 5 lines. Tarsus 1 inch; middle toe 1 inch, 2 lines; first toe 9 lines, and longer than the third; nails light flesh color; feet and legs deep red. Iris dark orange. Bill above, 1 inch, 1 line, but feathered to within 5 lines of the tip; reddish near the base, whitish near the tip. Head chocolateblue. Throat chocolate-white. Neck and breast blueish-chocolate with brilliant reflections. Back, belly, flanks, underwing-coverts and greater exterior wing-coverts light red color, the last faintly bordered with white. Lesser wing-coverts chocolate red, forming a bright shoulder spot of elliptical shape. Quill feathers dusky, tinged with lead. color on the outer vanes. 3rd primary longest. Upper and under tailcoverts blueish-lead color. Tail 5 inches; slightly rounded; of twelve feathers; dusky.

Individuals of this fine species, which in general contour, resembles Columba Enas, were found on the Rio Grande, from Matamoras to Camargo; these were shy, and only met with at intervals. They were again observed on one or two of the smaller water courses between the former place and Victoria, but never in flocks; nor were more than half-a-dozen seen anywhere in a single day while hunting over large extents. Their haunts were in the neighborhood of running streams or very large ponds of clear water: here four or five might be found scattered over some 20 or 50 acres ; thus showing little sociability even on their feeding grounds. But most frequently he is found alone, perched near the water, or with rapid wing shaping his solitary course across the extensive waste. His flight is extremely bold, as he pitches in wide irregular zig zags through the air, with a velocity scarcely to be surpassed. The meat for delicacy of flavor is not excelled by any of the family. 2. Basilosaurus, (communicated by Prof. Agassiz, from a letter recently received from M. A. Retzius.)-The following is an extract from a letter from Prof. J. Müller to Mr. A. Retzius, dated Berlin, March 24, 1847.

"The Hydrarchus, Koch, found in the tertiary formation in Alabama, is identical with Harlan's Basilosaurus and Owen's Zeuglodon cetoides.*

* Phocodon, Agassiz. Squalodon, Grateloup, in Leonhard and Bronn's Jahrbuch für Mineralogie, 1841, p. 830.

The crowns of the teeth, with which Owen was not acquainted, have a great resemblance to those of the seal; in the maxillary teeth they are cutting and many pointed; most of the maxillary teeth have double roots, but the anterior has, as in the seals, only a single root. In the anterior part of the jaw are found conical curved teeth, viz. an incisive and a canine, at least this is the case with the under jaw.

"As such teeth as those which are found in the Hydrarchus, occur in the tertiary formation in Malta, we may conclude that this animal belongs likewise to the tertiary formation of that island.

"I think I can positively show that the Hydrarchus is not a reptile, but a mammal belonging to a peculiar extinct family. It has the ear formed as in the mammals, viz. a helix, and a tympanic bone as in the whales. It has moreover two occipital condyles, and in the whole formation of the cranium no trace of reptile structure occurs, but on the contrary every thing is as in mammals.

"The vertebral column is very peculiar in its structure. The cervical vertebræ, probably more numerous than in any other mammal, are without perforations in their transverse processes; the ribs are only attached to the transverse processes of the vertebræ; at the central and posterior part of the column, the bodies of the vertebræ are unusually long, and must both at the anterior and posterior part of the extremities have been cartilaginous, inasmuch as we find here beneath the bony shell a mass of pure stone, while the central part of these vertebræ consists wholly of bone."

3. On the History of the Dodo and other allied species of Birds; by H. E. STRICKLAND, (Athen., No. 1029.)-He showed from historical data that each of the three islands of the Indo-African OceanMauritius, Rodriguez and Bourbon-was originally inhabited by peculiar species of brevipennate birds, all of which were speedily destroyed by the early colonists. Mauritius was the birthplace of the Dodo:the first notice of which was not, as erroneously stated, by Vasco de Gama, (who never visited Mauritius,) but by Van Neck, a Dutchman, in 1598. Several successive voyagers mention the bird, down to Cauche in 1638; and in the latter year a live specimen was brought to London, and was described by Sir Hamon Lestrange. The pictorial evidence respecting the dodo consists of four oil paintings:-one in the British Museum, without the artist's name; one at the Hague, and another at Berlin, by Roland Savery; and one at Oxford, by John Savery, his nephew. All these are evidently from one design,—and may have been drawn from a specimen which Van Neck brought to Holland. The osteological evidences of the Dodo consist of the foot in the British Museum, the head and foot at Oxford, and a head lately discovered at Copenhagen. The three former specimens were exhibited; and a cast of the latter had also been sent for the meeting; but was detained by the vexatious formalities of the London Custom House. The Oxford head and foot have been recently dissected; and from the characters thus exposed it is certain that the Dodo was not related either to the gallinaceous birds, the ostriches, or the vultures, as others have conjectured-but is closely allied to the pigeons. With the exception of its short wings, it approaches greatly to the Trerons, or fruit-pigeons; and still more to the Didunculus, a kind of pigeon from the Samoan