30 REPORT OF NATIONAL MUSEUM, 1920. 



Clapp collection of New England land and freshwater mollusks, 

 about 10,000 specimens purchased and presented by Mr. John B. 

 Henderson. The former, consisting of about 5,000 specimens collected 

 liv Mr. Thaanum and Mr. J. B. Langford, has long been known as the 

 best existing collection of authentically located marine Hawaiian 

 shells. As in previous years, the Bureau of Fisheries forms one of 

 the chief sources of our material of marine invertebrates, including 

 specimens collected during the cruises of the Albatross and the Bache 

 reported on by Mr. Sasaki, Dr. A. L. Treadwell and Dr. H. B. Bige- 

 low. Numerous other accessions from collectors and collaborators 

 were remarkable for the great number of types of new species added 

 during the year. 



The botanical collections accessioned include highly valuable ma- 

 terial from all over the world. Besides important North American 

 collections, there are represented plants from Mexico and Central 

 America, Colombia, British Guiana, Brazil, Argentina, Europe, 

 Africa, China, Sumatra, etc. The Department of Agriculture trans- 

 ferred 8,190 specimens, mostly the result of field work of the Bureau 

 of Plant Industry. The Forestry Commission of the Mexican state 

 of Sinaloa transmitted 887 specimens from little known parts of that 

 state. A large number of plants were obtained in exchange; the 

 largest lot consisting of 2,398 specimens received from the New York 

 Botanical Garden, mostly plants collected in Colombia by Rusby and 

 Pennell. Likewise in exchange there were acquired from the Botani- 

 cal Museum of the University at Copenhagen 923 specimens of Mexi- 

 can and Central American plants, chiefly material collected a long 

 time ago by Liebmann and Oersted and therefore of unusual historical 

 interest and value. 



The additions to the collections in the department of geology dur- 

 ing the year were 180 lots against 135 for the year previous, with a 

 decided increase in the number of specimens and their scientific value. 

 Of these accessions, 111 were gifts, 32 transfers, 25 exchanges, 2 were 

 collections by members of the force, 1 received as a deposit, and but 

 9 acquired by purchase. Among those of greatest importance were 

 gifts comprising ores of the rare metals, particularly tungsten and 

 molybdenum, secured chiefly through Mr. Frank L. Hess of the 

 U. S. Geological Survey, but honorary custodian in the Museum. 

 The donors included Mr. C. W. Purington, Vladivostok, Siberia; 

 Mr. J. G. Hibbs, Denver, Colorado; the Homestake Mining Com- 

 pany, Lead, South Dakota; the E. and S. Molybdenum Company, 

 Questa, New Mexico; and the Molybdenum Mines Company, Denver. 

 Other important additions were made by Dr. J. Morgan Clements of 

 New York, traveling in China in the interest of the Federal Trade 

 Commission, and Mr. M. L. Patterson, manager of the Thabawleik 

 Mines, Mergui, Burma. 



