The bituminous coal area of the United States is 133,132 square miles, or one 17th part of the whole. The bituminous coal area of British America is 18,000 square miles, or one 45th part; Great Britain, 8139 square miles; Spain, 3408 square miles, or one 52d part; France, 1719 square miles, or one 118th part; and Belgium, 518 square miles, or one 122d part. The area of the Pennsylvania anthracite coal formations is put down at 437 square miles; and that of Great Britain and Ireland anthracite and culm, at 3720 square miles. The anthracite coal of Great Britain and Ireland, however, is not nearly so valuable an article of fuel as the anthracite coal of Pennsylvania, nor does a given area yield so much as the latter.—New York Express. American Annual of Scientific Discovery, p. 271.

9. River Terraces of the Connecticut Valley.—At the meeting of the American Association in August, President Hitchcock of Amherst College, read a paper “On the River Terraces of the Connecticut Valley, and on the Erosions of the Earth's Surface.” He stated that his paper must be considered as containing a few facts and suggestions and not a finished theory. He has examined the valley from its mouth to Turner's Falls, and carefully measured the heights of the terraces. "As you approach the river you find plains of sand, gravel, or loam, terminated by a slope sometimes as steep as 35°, and a second plain, then another slope and another plain, and so on, sometimes to a great number. I find that these terraces occur in successive basins, formed by the approaches of the mountains upon the banks at intervals. Sometimes the basin will be 15 or 20 miles in width, but usually much narrower; and it is upon the margins of these basins that the terraces are formed. I have rarely found terraces more than 200 feet above the river, which would be in Massachusetts, about 300 feet above the ocean, and at Hanover, N.H.,[N30] about 560 feet. Nowhere do they exist along any river, unless that river has basins. As to the materials of which they are formed they appear exceedingly artificial. The outer or highest terrace is generally composed of coarser materials than the inner ones. They are all composed of materials which are worn from the rocks, but the outer terrace oftener is full of pebbles, some of them as large as 12 inches, while the materials of the inner seem reduced to an impalpable powder, like the soil of a meadow which is overflowed during high water. Whence did these materials originate? The materials were first worn from solid rocks, and afterwards brought into these valleys. The outer terrace appears to have been often in part the result of the drift agency. Afterwards, the river agency sorted the materials, and gave them a level surface, the successive basins having at that time barriers. The inner terrace appears to have been, at least in its upper part, the result of deposition from the river itself.

“I will now mention a few facts which I have observed. The terraces do not generally agree in height upon the opposite sides of the valley. The higher ones oftener agree, perhaps, than the lower ones. If formed, as I suppose, from the rivers, we should expect this. The terraces slope downwards in the direction of the stream. The same terrace which, near South Hadley, is 190 feet above the river, slopes until, at East Hartford, it is only 40 feet above the river, thus sloping 150 feet more than the slope of the river itself, in a distance of 40 or 50 miles. This shows that they could not have been formed by the sea or by a lake, for they would then have been horizontal. The greatest number of terraces observed is eight or nine. Generally there are but two or three.” President Hitchcock then gives his view of the precise mode in which these terraces were formed, illustrating them by references to other parts of our country, and concludes by a notice of the erosions of the earth's surface.—Annual of Scientific Discovery, 1850, p. 229.

ZOOLOGY.

10. Fossil Crinoids of the United States.—At the meeting of the American Association, 1849, a paper on the fossil crinoids of Tennessee, by Professor Troost, was read by Professor Agassiz.[90] The species embraced are not less than eighty-eight in number, of which only half a dozen have been described. It is the opinion of Professor Hall that all the silurian formations of New York, previous to the beginning of the geological survey, did not afford more than four or five. Now, about sixty species have been ascertained. Professor Hall mentioned the fact, that all the crinoids of the lower silurian rocks, with the exception of one species, have five pelvic plates, and we never find one with three, or any other number of these plates, before we reach the highest deposits. In Tennessee, the crinoids are so abundant, that Professor Troost states that he had been able to collect some 300 or 400 good specimens of seven or eight different species in a single morning. In relation to the abundance of these fossils in the United States, Professor Agassiz remarked, that it is not, perhaps, sufficiently appreciated of what importance, and of what immense value the study of these fossil crinoids may be for the progress of palæontology. American students should be proud of these materials, by which they will be able to throw so much light upon these almost extinct families by their personal investigations, which will not only render them independent of the palæontologist from abroad for information with regard to the succession of types, and the full illustration of these structures, but really afford correct standards for comparison. It is the more desirable that all these fossils should be made known, as the family of crinoids is so reduced in our days that we can form no idea of the living animals of that group, of their diversity of form, modification of character, and peculiarity of position, from the living type only. He doubted whether the number of crinoid heads of all species found in Europe, now existing in the Museums of Europe, is one-third the number of those which have been found by a single gentleman in Tennessee in one morning. Now, with such materials, consider what precise and what minute investigations could be made. And if these facts could be once fully ascertained and well illustrated, there is no doubt that the series of crinoids, and their succession in former ages, will be established from American standards, and will no longer rest upon the European evidence, which has often been derived from the examination of small fragments of those ancient fossils, found in unconnected basins for the most part, so that their geological succession could be ascertained only with great doubt and difficulty. In conclusion, Professor Agassiz would venture to say, that geologists who have had any opportunity to compare the position of the ancient rocks on this continent of North America with the corresponding deposits of Europe, would agree with him in saying that the geology proper, the stratography of North America, will afford the same precise and well authenticated standards for the appreciation of the order of succession of rocks, as fossils will for the order of succession of living beings.—American Annual of Scientific Discovery, p. 282.

11. Discovery of Coral Animals on the Coast of Massachusetts.—Professor Agassiz, while on an expedition in one of the vessels of the coast survey during the past summer, obtained by means of a dredge, from a depth of seventy-two feet, in the Vineyard Sound off Gay Head, several specimens of a coral with its animals. By great care and attention they were preserved alive in glass jars for more than six weeks, and afforded an excellent opportunity for an examination and observation of their structure and habits. These corals belong to the genus Astrangia, and have been named by Professor Agassiz, in honour of Professor Dana, geologist of the exploring expedition, Astrangia Dana.

This species presents two varieties. Some are of a pink or rose colour, others are white. The general form of the animal is a cylinder (as of all Polypi) resting on its base, and expanded on the upper margin; thus expanded it is about two lines in diameter. The number of tentacles is definite, but it is not always the same absolute number. It never exceeds twenty-four; in earlier periods of life there are only twelve, and there is even an epoch when there are only six.

It is, perhaps, a matter of surprise that the coral animal should have been found in this latitude. They teem in the warm latitudes; but there are very few species in the more temperate regions, and but for the opportunity afforded by the coast survey, the existence of these animals could not have been suspected on these shores. For many years, however, dead fragments had been found along the shores; but whether they lived there naturally or not had not been ascertained.—American Annual of Scientific Discovery, p. 311.

12. On the Circulation and Digestion of the Lower Animals.—Professor Agassiz states, that the circulation of the invertebrata cannot be compared to that of the vertebrata. Instead of the three conditions of chyme, chyle, and blood, which the circulating fluid of the vertebrata undergoes, the blood of that class of the invertebrata which he had particularly studied, the annelida or worms, is simple coloured chyle. The receptacles of chyle in different parts of the body are true lymphatic hearts, like those found in the vertebrata; this kind of circulation is found in the articulata and mollusks, with few exceptions, and in some of the echinoderms. In the medusæ and polyps, instead of chyle, chyme mixed with water is circulated; this circulation is found in some mollusks and intestinal worms. Professor Agassiz thinks, that the embryological development of the higher animals shews a similar succession in the circulating function. As regards the connection between respiration and circulation in vertebrata, the gills are found between branches of the blood system; in invertebrata, the chyliferous system is acted on by the respiration. The gills of fishes, therefore, cannot be compared to the gills of crustacea, articulata, and mollusks. In fact, no gills are connected with the chymiferous circulation. Animals having this circulation, have no true respiration. They have only tubes to distribute freshly aërated water to different parts of the body.—Proc. Bost. Nat. Hist. Soc.

13. Distribution of the Testaceous Mollusca of Jamaica.—The great number of species is remarkable. A few miles of coast, without the aid of storms, and without dredging, yielded 450 species. In the small bay of Port Royal, 350 marine species were found. A pint of sand, taken from a surface three yards long, contained 110 species. Probably there are 350 or 400 specimens of land shells, and two or three times as many of marine species. Extensive districts occur, however, which are nearly destitute of land or marine shells. They are accumulated in favourable stations.