Plate V.

Fig. 1. Longitudinal section or plan of parallel rows of cells, gray, in color, embedded in clear black Pennsylvania anthracite. But in the neighborhood of a, a faint suggestion of organized cellular structure, nearly at right angles to the other, may be seen.

Fig. 2. Plan of part of several other rows of the same structure as in figure 1, and occuring on the same fractured surface of the same specimen of coal, at about one fourth of an inch to the left of the left hand end of figure 1.

Note. These organisms seem to be rare in the coal: they are the only specimens of the kind that the author has met with. Presumably they are of vegetable origin.

Fig. 3. An approximately vertical section of part of a bright, nearly black lamina in Pennsylvania anthracite, in dark gray coaly matrix. The specimen or fragment found, seems to be composed of some sixty separate bands or strands lying parallel with and practically in touch with one another. The point a, seems to be an edge or margin of the thing, the other end being broken off at b c. At d, something in the shape of an intruder appears and has created a deformity in the specimen at that place. Likewise a smaller disturbance appears near the middle of the figure.

Figs. 4, 5 and 6 show the character of the internal structure of the units as they are more or less distinctly revealed at or near to the several positions, e f and g respectively, Thus the specimen is apparently composed of but one kind of fibres or cells which are long rather than short, and towards the margins of the units become quite fine or hairlike in texture.

Note. This fossil seems to be scarce in the anthracite of Pennsylvania. In specimens of anthracite from South Wales, the author has observed rather similar forms and organization.

REVIEW OF RECENT GEOLOGICAL LITERATURE.

Fossil Flora of the Lower Coal Measures of Missouri. By DAVID WHITE. Monograph XXXVII, U. S. Geol. Surv. 1899.

In fullness of treatment, references, text and illustrations, and especially in its stratigraphic application, this is the most important work on Paleozoic plants yet published in this country. The only publication relating to American Paleozoic plants which can in any way be

compared to it is the Coal Flora, by Lesquereux, published by the Pennsylvania survey. To students and collectors of coal plants, especially in the Lower Measures, this book is invaluable, and it is a much needed example in methods of collection, study and publication. It will make clear the fact that little can be done in satisfactory classification and discussion of a Carboniferous flora without a great body of material for comparison, and without recourse to a very extensive literature. However discouraging this may be to many students, it is nevertheless true. The United States National Museum has already become the great depository of coal plant material in this country, and, with its great number of American types, will doubtless remain a center of systematic work in this field. The experience, the knowledge of the plants and the paleontological ability shown in this volume place its author in the lead among American students of Paleozoic plants. Whoever has attempted the determination of Carboniferous plant species with no other aid than the earlier memoirs on the younger Paleozoic floras realizes the insufficiency of a great part of the descriptions and the lack of data as to the localities or horizons of the fossils. A large proportion of the collections of the past, even those which formed the basis of the writings of Lesquereux, were so incomplete, so. carelessly collected, their stratigraphical origin so generalized or indefinite, that they are largely valueless for correlation. What is imperatively needed is full collections of plant remains from exactly known horizons, and over wide areas. There remains plenty of work of the right kind to be done.

The book consists of 73 quarto plates, nearly all of them being photographic reproductions of plant remains, and 307 pages of quarto text. The first ten pages are given to introductory description of the collection and localities; the last 32 pages are general discussion of the geological significance of the flora and its correlation, while the rest of the book, 265 pages, is detailed description of the species. This biological portion of the work is admirable in its fullness, refinement and lucidity. The full bibliography and synonymy are evidence of the detail and difficulty of the study and of the scholarship of the author.

Nearly all of the plant material is from Henry county, Missouri, large in amount and covering many years of collecting, thus representing fairly the plant life of the coal basin.

Dr. J. H. Britts of Clinton, Mo., collected the larger part of the material, which was mostly derived from two horizons about 45 feet apart, and separated from the old Mississippian (Lower Carboniferous) land surface by less than 100 feet of sediments. The flora is "representative of that division of the Carboniferous resting on the Pottsville series in the northern and northeastern coal fields."

The species described, number 123, representing nearly all the common genera of the middle Carboniferous of Europe and America. They are distributed as follows: Algæ, 2; Fungi, 2: Ferns, 70; Equiseta 19; Lepidodendrids, 12; Sigillarids, 2; Tæniophyllids, 2; Gymnosperms, IO. The author draws attention to the preponderance of ferns, es

pecially Sphenopteris and Pecopteris; he notes that with two unimportant exceptions all the plant species of the Missouri flora are at least varietally unlike the plants from the Pottsville series; and that a large proportion have a range through considerable thickness of American Mesocarboniferous, giving in consequence little aid in correlation of horizons. He finds, however, some local modifications of species having wide vertical range which do aid in correlation.

Of the 123 enumerated species 39 are peculiar to the Missouri flora,. as compared with American localities, and of these, 24 are new species. For comparison with the floras of other basins in the United States 48 species of more limited vertical range are selected, and the final conclusion is that the flora represents a time subsequent to that of the lowest coals of the Lower Coal Measures of the eastern districts, as the Morris coal of Illinois, the Mazon Creek beds, and the Brookville and Clarion coals of Ohio and Pennsylvania, but probably an earlier date than the Darlington or Upper Kittanning of Pennsylvania and Ohio; also that the Henry County flora is nearly contemporaneous with the "D" or Marcy coal of the Northern Anthracite field, though possibly as old as the "C" coal. The unconformity in Missouri between the Henry County coals and the underlying Eocarboniferous surface represents no less time than was required for the deposition of the Pottsville series and the Clarion group of the lower productive Coal Measures, which have a thickness in southern West Virginia of 2,400 feet.

In comparison with European floras the author regards the Missouri flora as having a position between the Middle and Upper Coal Measures of Great Britain, or corresponding to the "transition beds," and to the upper zone of the Valenciennes coal field in the FrancoBelgian basin.

As evidence of the value of paleobotanical correlation, it is to be noted that the horizons in the British and the Westphalian coal basins which had been correlated by the European paleobotanists, are now found by the entirely independent studies of David White to be in each area also contemporaneous with this American flora.

As there is a strong contrast between the floras of the Pottsville series and those of the immediately overlying coals of western Pennsylvania and westward, and since the Lower Coal Measures of Great Britain and the Vicoigne (lower) zone of the Franco-Belgian basin are not known to be represented in the American bituminous region, the author suggests that the European beds may be represented in the variable strata of the upper benches of the northern Pottsville, and that they are probably represented by the Lower Coal Measures (Kanawha series) in the Kanawha region in West Virginia. The plants of the latter series, which he is now studying, promise to represent, in America, the Lower Coal Measures flora of England and Westphalia. (See below, page 59.)

Another interesting suggestion of the author is that many species, and even genera, of the Mesocarboniferous plants were evolved in