Discusses history, specimens, habits, economic status, food, and pelages of American harvest mice. Lists locations and provides a key to species and subspecies, and provides species descriptions.

Discusses habits, economic status, morphology, variation, history, and specimens of North American rice rats. Provides a key and descriptions for species and subspecies.

Discussing the potential for Mexico to be used as a uranium source.

Seven new subspecies of the white-winged dove (Zenaida asiatica) are described. The patterns of these recoveries are an invaluable aid to understanding racial distribution of this species. The extent of migration that breed in Central America is not yet adequately known. The range of the doves extends as far north as the southwestern United States.

From introduction: "Result of a study of the spiny pocket mice in the collection of the Biological Survey, now numbering nearly 1,000 specimens, supplemented by about 130 in the United States National Museum and from various sources."

From abstract: Manganese has been reported from 335 deposits in 20 of the 30 States and Territories of Mexico. The production of manganese ore prior to 1942, according to published figures, amounted to about 54,000 tons. For the year 1942 production rose to 35,000 tons, for 1943 to 70,503 tons, and for 1944 to 80,671 tons; but for 1945 it dropped to a little less than 52,000 tons, and during 1946 it continued to drop. Up to the end of 1941 Chihuahua had produced about half the manganese ore from Mexico; San Luis Potosi produced about 17 percent, and Baja California and Zacatecas each about 10 percent. In 1942 Baja California became the chief producer; Durango, Chihuahua, and Zacatecas each yielded somewhat less. During that year the ore came from 76 deposits, of which only 30 yielded more than 500 tons each.

From introduction: "Revision to include all known hares and rabbits of North America from Isthmus of Panama to north Greenland."

Classification of more than 3,000 bats to enable correct specimen identification based upon material contained in the collection of the Biological Survey of the U.S. Department of Agriculture.

From letter of transmittal: "The work consists of a systematic study of all the members of the genus, and includes keys for the identification of the various forms, together with the necessary illustrations, and maps showing the geographic distribution of the species."

From introduction: "Synopsis of American voles based on a study of between 5,000 and 6,000 specimens from more than 800 localities."

From introduction: Study of about 1000 gopher specimens, enabling for the first time actual comparison of various species.

From introduction: "Result of a study of the wood rats in the collection of the Biological Survey, numbering over 3,000 specimens, including topotypes of most of the species."

Brief summary of the habitat, habits, food and economic status, measurements, subfamilies, and subgenera of genera Sorex and Microsorex.

From introduction: "In this paper are assembled and summarized many subjects relating to the copper industry in North America. Production of mines and districts, history of the industry in North America. Production of mines and districts, history of the industry, geology, of the principal deposits, and mining methods and costs are discussed."

Describes habits, predators, morphology, sexual variation, pelages, and distribution of pocket gophers. Describes genera and group relations. Describes, lists locations and distribution, and provides a key for species and subspecies.

Brief summary of three genera of American shrews, including characteristics, habits, habitat, and skull, jaws, and teeth illustrations.

A report about recorded shock waves observed or felt on Mount Hamilton, and all those reported to the Lick Observatory by letter, as well as newspaper reports of such earthquakes that occurred in California during that year.

From Scope of Report: "During the summer of 1940, 34 days were spent in a preliminary study of the quicksilver deposits in the Steens and Pueblo Mountains. Nearly all of the quicksilver prospects were examined and mapped, and the general geology of the east flank of the mountains from north of Andrews to Denio was reconnoitered."

Brief description of the Tres Marías Islands, Mexico, including mammals, birds, reptiles, crustacea, and plants found there.

From introduction: "Classification changes to skunks of genus Chincha in order to clear up confusion resulting from previous attempts at classification."

Summary of the geographic distribution, habits and economic relations, and descriptions of the subspecies of the North American Sciuridæ.

From outline: The primary object of this bulletin is the presentation of a summary of our present knowledge of the North American Cretaceons and a discussion of the system as it is developed on this continent, discussion of or direct reference to the details of the system as it is developed in other parts of the world being omitted.

Report issued by the U.S. Bureau of Mines discussing the building material, dimension stone. As stated in the introduction, "the pertinent properties and principal specifications for stone are described along with exploration, mining, finishing, and use technology. A brief history and geologic background are also included" (p. 2). This report includes maps, tables, illustrations, and photographs.

Report presenting a study of stoping methods and costs and summarizing the data obtained in earlier publications and those obtained during investigations in the field that apply particularly to stoping.