Cahaba field at 230 square miles, the average thickness of workable coal over the entire field would probably scarcely attain fifteen feet. This estimate, so much lower than we have been accustomed to see stated in reports and newspaper articles, is probably not very different from the thickness which the same method of estimating would give for any of our other bituminous coal fields. "The enormous thickness of the coal-bearing rocks in the Cahaba field, being estimated at over 5,000 feet, has no parallel in the Warrior coal-field." Record of four borings in the Warrior field show sections of from 400 to 600 feet of strata, including four, seven and eleven coal-horizons.

Prof. Lesquereux furnishes a list of 57 species of coal-plants, (of which 12 are named as new,) and remarks upon the very low position in the Coal-measure series to which they must theoretically be assigned, a few species, such as Sternbergia, Lepidodendron Weltheimianum and Asterophyllites gracilis, ranging down even into the Devonian. This corresponds with the suggestions already made, by several geologists, that the coal-measures of the Southern States are all very low in the series, the whole having been called "sub-conglomerate" by some writers. We should prefer, however, some more certain evidence on this point than has yet been produced. The surveys of Alabama, Georgia and Kentucky, now in progress, will leave but a short gap (in northern Tennessee) between the well-known fields of Pennsylvania and Ohio and the southern extremity of the system.

The body of the report is occupied with details of County-work, mostly in the Silurian areas of the State. Some analyses of ores are given, besides lists of elevations. There is also a valuable paper by A. R. Grote, on the cotton-worm (Aletia argillacea Hübner) which is preliminary, the author states, to a more extended history of the worm. Mr. Grote writes from observations

in Alabama on the habits of the worm, and also from a study of it elsewhere. He is an excellent entomologist, and if his reviews are continued in the survey, will add greatly, by his study of the insects injurious and beneficial, to the value of the State Reports.

We understand that the State appropriation, for the work thus reported on, is only $500 a year to cover the travelling expenses of the geologist during the vacations of the State University, in which institution he is a Professor. The volume may therefore properly be accounted a personal contribution to the cause of science.

4. The Geological Record for 1874.-An account of works on Geology, Mineralogy and Paleontology, published during the year. Edited by WILLIAM WHITAKER, B.A., F.G.S., of the Geological Survey of England. 398 pp. 8vo. London, 1875. (Taylor & Francis.)-Mr. Whitaker, the editor of the Geological Record, has had able co-workers, and has produced a volume which will be found of great value to all of all lands that are interested in the progress of geological science. The sub-editors are the following, all members of the Geological Society: W. Topley, G. A.

Lebour, F. Drew, and R. Etheridge, Jr., for Descriptive Geology; Professor A. H. Green, for Physical Geology; F. W. Rudler, for Mineralogy and Petrology; and L. C. Miall, Prof. H. A. Nicholson, and W. Carruthers, for Paleontology. The number of works and memoirs mentioned by title is very large, and, for much the larger part, short abstracts are given, which appear to have been carefully prepared. American publications are included, as well as those of other continents, and are judiciously treated. Some omissions we note, of papers in the Publications of Societies. This volume is to be the first of a series of Annual Records, and that for 1875 is already far advanced.

5. Report on the Geology of a portion of Colorado examined in 1873; by Prof. J. J. STEVENSON. 376 pp. 4to. Part IV of Lieut. Wheeler's Survey Report, vol. III. Published March 4, 1876.-Prof. Stevenson treats, in his report, of the general physical features of Colorado, of the various rock formations and mineral springs, and of the structure and age of the Rocky Mountain System and brings forward much that is of interest. Under this last head, the new conclusion is advanced that there was an era of mountain-making in the Rocky Mountains at the close of the Carboniferous age, synchronous with that in which the Appa lachians were formed. The facts brought forward in its support appear to us to be too few and from too limited an area to establish fully its truth against the opposing statements of other Rocky Mountain investigators. If an epoch of mountain-making then occurred, it ought to be registered in an extensive series of obvious facts. We see in the Appalachians-in their breadth exceeding 100 miles, their length several hundreds, with upturnings everywhere-an example of an individual mountain-chain (i. e., one made in a single mountain-making operation); and also a display of the manifest evidences of disturbance which such an area should bear. We have, further, an illustration of the fact that such an "individual" cannot have narrow confines, because the crust of the earth has been-certainly since Silurian times-too thick to bend in a narrow trough or geosynclinal (the trough in which the deposits constituting the mountains were accumulated). We shall look with great interest for the results that may hereafter be published by other observers on this interesting question.

J. D. D.

6. Das Gebirge um Hallstatt. Erster Theil; Die MolluskenFaunen d. Zlambach und Hallstätter-Schichten. II Heft mit 38 Lith. Tafeln. Von EDMUND MOJSISOVICS VOn Mojsvár, Chef-Geologen d. k. k. geol. Reichsanstalt. 4to. Vienna, 1875.-This part of the great work on the peculiar fossil fauna of the renowned locality of Hallstatt is worthy of its predecessor previously noticed in this Journal. It contains the most complete series of figures and descriptions of the genus Arcestes yet published. Thirty-four plates are devoted to the illustration of this group and the specimens are, for the most part, very perfect. This has enabled the author to exhibit a very perfect series of a multitude of various forms all

having perfect apertures, and his plates are the most perfect demonstration, which we have yet seen, of the importance of the contours of the aperture in the classification of sub-groups. The author divides the genus Arcestes into several divisions according to the peculiarity of the sutures and gives complete tables of the geological and geographical distribution of the species. In fact the stratigraphical paleontology is treated in the most perfect manner. Any criticisms of the zoology of the work would be out of place and inapplicable, since it is essentially, as are all the later German paleontological memoirs on this and kindred subjects, paleontological geology; the differences of the animal remains being invariably the aim of all the researches, with the view of establishing data by which the different strata may be distinguished one from another, and the peculiarities of the faune noted. Two new genera are described, Didymites and Lobites. The latter being related to the true Arcestes in about the same way that Scaphites is to the typical Ammonites. Whether this will eventually hold or not is doubtful, since, as Quenstedt has shown in his master-work on the Jura, such forms are intimately connected with normal forms, sometimes not even specifically separable according to the generally accepted methods of classification.

A. H.

7. Rammelsberg: Handbuch der Mineral-Chemie. 2d edition, 980 pp. 8vo. Leipzig, 1875.-The second edition of Rammelsberg's valuable work on mineral chemistry is an indispensable volume to all interested in the progress of mineralogy. The general plan adopted by the author is essentially that of the first edition (published in 1860), the most important changes being those which strict conformity throughout to the principles of the new chemistry has required. The first volume (136 pp.) contains the general treatment of the subject of mineral chemistry, with a detailed discussion of the principles of isomorphism and heteromorphism. The second volume (744 pp.) takes up the mineral species in order, giving under each the most of the analyses published, especially those of recent date. For each analysis the atomic ratios of the different elements have been calculated in full, and from them the formulas are deduced. The author has been so long an authority in mineral chemistry that his present conclusions on many disputed points, though occasionally appearing somewhat arbitrary, will have great weight with all.

E. S. D.

8. Einleitung in die Krystallberechnung, VON CARL KLEIN; zweite Abtheilung, pp. 209-393. Stuttgart, 1876.-The first part of Professor Klein's valuable work on crystallography was noticed in a recent number of this Journal, (III, xi, 68.) The present part includes a detailed description of the methods of calculation applicable to the monoclinic, triclinic, and hexagonal systems, the whole being characterized by the same clearness and thoroughness to which attention was before called. A chapter upon the drawing of crystals forms the conclusion of the work.

E. S. D.

III. BOTANY AND ZOOLOGY.

1. Phænological observations in Giessen; by H. HOFFMANN. (Phän logische Beobachtungen in Giessen, von H. Hoffmann.) -We do not know any single English word for the kind of observations here recorded, and therefore we shall adopt that which our author has borrowed from Greek. This pamphlet of 32 pages gives the date when the leaf and flower-buds of over two hundred plants opened; the fall of the blossom; the ripening of the fruit, and the fall of the leaves. The observations in some cases extend through twenty years or more. The author has also noted the dates of the appearance of butterflies, birds, etc. The author submits his work as a contribution to the store of facts required by the student of vegetable climatology, but does not give any conclusions of his own except the following:

In the case of plants in a given locality, the average of a few years is very nearly the same as the average of many, e. g. : The "first flowers" of the following species appeared on the days given below as means:

of 15 years,

26 June,

of 9 years,

25 March,

In only one of the cases collated is there to be observed a difference of more than one day.

Prunus avium, average of 8 years,.

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14

23 April.

21

2. Bulletin of the Bussey Institution, Harvard University. Part V. 1876.-This finishes the first volume, of 453 pages, and is therefore properly supplemented by a copious index. In articles No. 18, 19, and 20, Prof. Storer continues his valuable and practical chemical papers-the notice of which we leave to another hand. Papers No. 21 to 24 are by Prof. W. G. Farlow, as follows:

On a Disease of Olive and Orange Trees occurring in California in the spring and summer of 1875.-It proves to be the work of a fungus, Fumago salicina, which has been known and given trouble in Europe since the year 1829. In an excellent plate Prof. Farlow represents the stylospores, mycelium, pycnidia,

and conidia.

On the American Grape Vine Mildew.--It appears that the Oidium Tuckeri, which has been so disastrous to the vines of

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Europe and Madeira, and which is "the conidial form of some species of the Ascomycetes, probably some Erysiphe," although supposed to have come from America, is not a common or conspicuous infestor of our native vines; but that the commonest, at least in New England, is Perenospora viticola, which is limited to the leaves and stems, and does not attack the fruit. Being often found on every leaf, of a vine, it would be expected to injure the grape crop. Such, however, is not the case. The fungus does not attack the grapes themselves, nor does it, at least in New England, appear until about the first of August, and its withering effect upon the leaves is not very evident before September. As far as out-of-door grape culture in the northern States is concerned, we are inclined to believe that, practically, no harm is done by Perenospora viticola, but that, on the contrary, the fungus is really beneficial. Our native vines have a luxuriant growth of leaves; and the danger is that, in our short summers, the grapes may not be sufficiently exposed to the sun to ripen. But the Perenospora arrives, with us, at a time when the vine has attained its growth for the season, the important point being then to ripen up the grapes which are concealed by the foliage. By the shriveling of the leaves, the Perenospora enables the sun to reach the grapes without loss to the vines, as is shown by the fact that the vines continue to live on, year after year, without apparent injury." The botanical history, literature, and forms of this fungus are fully illustrated, two plates show the structure and fructification of this and some allied species; and a synopsis of the halfdozen species of Perenospora detected in the United States, and five of Cystopus, is appended.

List of the Fungi found in the vicinity of Boston. Confined to the species which have come under the author's own observation.

The Black Knot (of Plum and Cherry trees). This interesting and important memoir is illustrated by three beautiful plates, showing this disease in various stages, and the whole structure, development and fructification of Sphoria mortosa of Schucinitz, the fungus which produces this black knot, which so deforms and injures plum and cherry trees throughout the Northern States and Canada. The remedy is the knife or the axe. For prevention Dr. Farlow recommends the extirpation of choke cherry trees, upon which the pest largely breeds in the vicinity of Boston. Farther west it would all the more be necessary to destroy all the wild plum-trees (Prunus Americana), which are fearfully infested.

No. 25, the last paper of the volume, is Prof. Sargent's

Report of the Director of the Arnold Arboretum ;-from which we learn that: "Probably over 100,000 ligneous plants have been raised during the nine months," and as many as 5,542 trees and shrubs have been presented to various establishments and individuals throughout the United States interested in agriculture," besides those sent to Kew and elsewhere abroad. A catalogue of the species raised is appended.

A. G.