sissippi, mainly with a view to ascertain the geological age and mode of occurrence of the rock-salt deposit of Petite Anse. In the absence of definite data concerning the general geology of Louisiana, his observations on the formations of the coast (an abstract of which was published in the American Journal of Science, January, 1869) demonstrated, so far as the salt deposit was concerned, only the fact that in point of age it was anterior to the drift. The impulse thus given to geological research in Louisiana, however, soon led to further exploration's. By subscription, and a special appropriation obtained from the commissioners of immigration of the State, the New Orleans Academy of Sciences raised a fund for the purpose of enabling Professor Hilgard to make a general geological reconnaissance of Louisiana, which was executed in May and June, 1869. This enabled him to communicate to the American Association for the Advancement of Science, at its Salem meeting, a general sketch of the geology of Louisiana. Almost simultaneously with the organization of Professor Hilgard's second exploration, steps were taken by the faculty of the University of Louisiana to secure legislative aid for a geological and physical survey of the State. The latter is now in progress, and the second annual report on the work will soon be published.

As regards the rock-salt deposit, Professor Hilgard's observations in Northern Louisiana point to the conclusion that it is but one of a series of cretaceous outliers, traversing the State in a northwest and southeast direction, and indicating the existence of an ancient ridge which must have exerted an important influence upon the physical conformation of the Lower Mississippi Valley. The remarkable gypsum and sulphur deposits of Calcasieu are likewise, in his opinion, referable to the same age. Professor Hilgard has nearly completed a final memoir on the geology of the Petite Anse region for publication by the Institution; the results of his simultaneous exploration of the Lower Mississippi and delta having been communicated to the American Assocition at the Troy meeting, and subsequently presented to the American Journal of Science.

Dr. Horatio C. Wood, of Philadelphia, having completed an elaborate work on the fresh-water algae, principally of microscopic forms, presented it to the American Philosophical Society and also to the Academy of Natural Sciences of Philadelphia, but the expense of publication prevented either of these societies from undertaking it. It was therefore offered to this Institution, and after a critical examination has been accepted for publication. As a systematic description of the freshwater algae of North America it will form a complement to the great works on the marine algae, by Dr. Harvey, published some years ago by the Smithsonian Institution. It will be copiously illustrated by drawings, made principally under the microscope and will serve to illus trate an obscure department of botany, as well as to furnish the means by which investigators of minute microscopic organisms may make the

comparison of fossil and recent forms, a subject which is now attracting much attention in Europe and America.

The eighth volume of Miscellaneous Collections contains the following papers:

1. Monographs of the Diptera of North America. Part IV. Prepared for the Smithsonian Institution by R. Osten Sacken. 8vo, pp. 358. Four plates and seven wood-cuts.

2. Catalogue of the Orthoptera of North America described previous to 1867. Prepared for the Smithsonian Institution by Samuel H. Scudder. 8vo, pp. 110.

Pulmo.

3. Land and Fresh-water Shells of North America. Part I. nata Geophila. By W. G. Binney and T. Bland. 8vo, pp. 328, and 544 wood-cuts.

4. Arrangement of Families of Birds. Adopted provisionally by the Smithsonian Institution. 8vo, pp. 8.

5. Circular to Officers of the Hudson's Bay Company. 8vo, pp. 6. 6. Suggestions relative to Objects of Scientific Investigations in Russian America. 8vo, pp. 10.

7. Circular relating to Collections in Archæology and Ethnology. Svo, pp. 2.

8. Circular to Entomologists. 8vo, pp. 2.

9. Circular relative to Collections of Birds from Middle and South America. 8vo, pp. 2.

10. Smithsonian Museum Miscellanea. Pp. 88.

The ninth volume of Miscellaneous Collections contains

1. Bibliography of North American Conchology previous to the year 1860. Prepared for the Smithsonian Institution by W. G. Binney. Part II. Foreign Authors. 8vo, pp. 302.

2. Catalogue of Publications of Societies and of Periodical Works belonging to the Smithsonian Institution. Deposited in the Library of Congress, 1866. 8vo, pp. 596.

In accordance with the plan adopted by the Institution of furnishing facilities and means of identifying specimens of natural history in its different departments, an arrangement was made with Professor De Saussure, of Geneva, Switzerland, the highest authority on the class of insects known as hymenoptera, (of which the principal forms are wasps, bees, &c.,) to prepare a monograph of this part of entomology. Large collections have been sent to him for the work, to which he has devoted several years of gratuitous labor. The first part of the manuscript was completed in the French language in 1863, and for translation was placed in the hands of a competent entomologist, Mr. Edward Norton, of Farmington, Connecticut, who volunteered his services from a desire of advancing science. This part of the memoir was prepared for the press in 1864, but as Mr. Norton was obliged to be absent from the country several years, the printing was delayed until his return, in order that the proof-sheets might be properly corrected. By this time, however,

so much new material had been collected it was thought advisable to refer the work anew to Professor De Saussure, from whom it has again been received, and after having been a second time revised by Mr. Norton will soon be sent to the press.

The Institution in carrying out its original plan of the preparation of manuals of natural history, has thus made provision for publications on the coleoptera, lepidoptera, neuroptera, diptera, orthoptera, and hymenoptera. Of the few remaining orders, a similar monograph of the hemiptera, by P. R. Uhler, esq., has been prepared, and will be published when the funds will permit.

For many years the Institution has intended, in consequence of the scattered nature of the accounts of the botany of the region west of the Mississippi, and the absence of any text-book in which correct descriptions could be found, to publish a complete list of the plants, with all the synonyms and species. For a working botanist, engaged in the study of our western plants, the search for what has been written takes more time and labor than all the rest of his work, besides which there is always the probability of overlooking some writings of importance. The design has not heretofore been carried out, on account of the pressure of othe operations, but recently the great need of this aid to botanical research having been urged on the Institution by some of the principal botanists of the country, arrangements have been made with Mr. Sereno Watson, of New Haven, to prepare the work in question. The expense of preparation will be borne by private subscription, the Smithsonian Institution paying for the clerical labor and for the publication. Mr. Watson is esteemed highly competent for the duty intrusted to him, and is favorably known from his labors as botanist of the exploration of the fortieth parallel, under Clarence King, esq. Good progress has been made in the work, and during the year we expect the manuscript to be completed. In still further pursuance of the plan initiated by the Institution of furnishing aids for the arrangement of collections, as illustrated by its series of check-lists of specimens, an article by Professor Theodore Gill is in process of publication, entitled "An Arrangement of the Families of Mollusks." His system has been adopted provisionally as that by which the extensive collections of the Smithsonian shells are to be arranged and has been approved by some of the principal zoologists of the country. To extend its benefits, and furnish a similar guide to other museums, the list embraces families, recent and fossil, accepted by the best naturalists of the day, although embodying results of special investigations made by Professor Gill and Mr. Dall at the Institution.

The Annual Report for the year 1869 was printed as heretofore, by order of Congress, but there was a reduction of one thousand in the number of extra copies usually furnished to the Institution. This reduction must have been the result of inadvertence, as we have long urged upon Congress the great demand for the document as a reason

for the increase of the edition, and have been assured by many Senators and Representatives that this would be made. The applications for the report have become so numerous that it is impossible to supply all who are entitled to receive it. In this connection the propriety should be urged upon Congress of ordering new editions of such of the reports as have been stereotyped. The printing of these could be done at very little expense, and would enable the Institution to furnish volumes, for which there is daily application from members of Congress in behalf of libraries and public institutions, to complete sets of the series.

In addition to the report of the Secretary, giving an account of the operations, expenditures, and condition of the Institution for the year 1869, and the proceedings of the Board of Regents, it contains the following articles: Memoirs of Kepler, Thomas Young, Auguste Bravais, C. T. P. Von Martius, and Stefano Marianini; an original paper on the chemistry of the earth, by T. Sterry Hunt; articles on the electrical currents of the earth; phenomena of flight in the animal kingdom; the northern seas; report on the transactions of the Society of Physics and Natural History of Geneva; an original article relative to Coronado's march in search of the seven cities of Cibola, and a discussion of their probable location; social and religious condition of the lower races of man; principles and methods of palæontology; remarks on the Cara Gigantesca of Yucatan; forests and their climatic influence; meteorites; remarkable forms of hail-stones in Georgia; eruption of the volcano of Colima. It is proper to remark that the article on the flight of birds was translated from the French by Mr. W. H. Dall, whose name was accidentally omitted at the head of the article.

For the purpose of forming a general map of the North American Continent, exhibiting the plains, mountains, valleys, &c., the Smithsonian Institution has collected a large amount of material relative to altitudes, which has been placed in the hands of W. L. Nicholson, esq., topographer of the United States Post Office Department, to be discussed and elaborated.

There must, however, still remain in the hands of individuals and corporations records of an important character, which would be of great value in properly carrying out the enterprise. The correspondents of the Institution are requested to send to it printed copies or original ́manuscripts of records, especially of plotted profiles or maps, pertaining to this subject.

In stating the heights, as furnished by surveys for railroads, whether actually constructed or only projected, it is desirable that the levelings be referred to some known point on connecting or intersecting roads, or to the water-surface (high water, low water, or mean tide) of the ocean or of one of the great lakes, or to the level of a noted stage of water (high or low) of some river. The crossings of the water-courses, ridges, and summits are particularly desired, as well as all considerable and characteristic changes of level, giving, where much difference exists,

both grade-line and original surface; the levels of all intersections with other roads are important as means of comparison, and for checking results. Due credit will be given to all contributors to this work.

Exchanges.-The system of international exchanges, established by the Institution, has been continued with unabated zeal during the past year. The number of foreign establishments to which the Smithsonian and other publications are distributed, and from which returns are received now amounts to over seventeen hundred. It includes not only all the first-class libraries and societies which have established a repu tation, but also a large proportion of the minor institutions of the Old World. The following table exhibits the number of foreign institutions. in each country with which the Smithsonian Institution is at present in correspondence:

During the year 1870, 1,805 packages, containing many thousand dif ferent articles, were transmitted to foreign countries. These packages were contained in 121 boxes, having a cubical content of 1,189 feet, and weighing 31,383 pounds. The parcels received at the Institution for parties in this country numbered 3,705. The separate volumes contained in these parcels would largely increase the number, the Institu tion having received 5,182 articles for its own library. The war between France and Germany, which commenced in July, affected, in some degree, the number of packages received from these countries, and it is probable that the result of this unfortunate conflict will be still more marked in the diminution of the number of scientific publications which may be received from Europe in the year 1871. The Smithsonian packages are passed through all the custom-houses of the world free of duty. The only exception which existed at the date of the last report was that of Italy, and through the intervention of the American minister, Hon. Mr. Marsh, the Italian government has since granted the same privilege.