38 KEPORT OF NATIONAL MUSEUM, 1888. 



primary object of this expedition being to collect fossil plants in this 

 region. About 25 species of mosses and 300 species of flowering plants 

 were also obtained. 



During the past two years a special study of the flora of the District 

 of Columbia has been made, one of the results of which is that there 

 are now in the herbarium about 1,000 species of plants from this locality. 

 The curator states that several valuable accessions have been received, 

 the principal one being the collection made by Edward Palmer, in 

 Mexico. This contains 768 species. Second in size, but none the less 

 valuable, is the Mexican collection made by C. G. Pringle. 



The routine work of the department has been well attended to, and 

 the present state of the collection is very satisfactory. 



During the year 1,538 specimens of fossil plants have been added to 

 the collection, and 19 entries have been made in the catalogue. There 

 have also been received 6,000 specimens of recent plants. These have 

 been catalogued under 347 numbers. 



MINERALS. 



Prof. F. W. Clarke, honorary curator, reports that gifts of minerals 

 have been received from many sources, and that valuable additions 

 have been made to the collections of meteorites and gems. 



A collection of gems and precious stones was prepared for exhibition 

 at the Cincinnati Exposition, and some valuable additional specimens 

 were obtained. 



The largest accession of the year is the collection bequeathed by the 

 late Dr. Isaac Lea. The U. S. Geological Survey has, as usual, made 

 large and valuable contributions to the collection, especially important 

 being the minerals collected by officers of the Survey at Denver, Colo- 

 rado. 



The greater part of the routine work of the department has been car- 

 ried on by Mr. William H. Yeates, assistant curator, who has devoted 

 much time to cataloguing and labeling. 



During the year 3,295 specimens have been added to the collection, 

 and 347 entries have been made in the catalogue. 



LITHOLOGY AND PHYSICAL GEOLOGY, 



The curator, Mr. George P. Merrill, has devoted the greater part of 

 his time to the preparation of the exhibition, study, and duplicate series. 

 He has also completed the manuscript for a hand-book of the building- 

 stone collection. This contains not only a catalogue of the Museum 

 collection, but also a description of the principal quarries in the United 

 States, information in regard to the structure and composition of rocks, 

 methods of quarrying, results of pressure tests, and other associated 

 subjects. 



During the year the storage material belonging to this department 



