REPORT OF THE SECRETARY 13 



ber collection of Hemiptera, amounting to 35,000 specimens and in- 

 cluding some types and paratypes. Other important entomological 

 material included over 2,500 insects from Colombia, collected by 

 Curator E. A. Chapin in 1946; about 2,000 insects collected by Dr. 

 J. P. E. Morrison as a part of Operation Crossroads biological investi- 

 gations; nearly 400 aquatic insects collected in Guatemala by Dr. 

 Robert R. Miller ; about 16,000 specimens of Mexican and Canal Zone 

 insects collected by N. L. H. Krauss ; and 65,000 specimens transferred 

 from the United States Department of Agriculture. 



A great variety of marine invertebrates was received but the largest 

 accession in this division was the gift of the Horton H. Hobbs private 

 collection of crayfishes. Comprising about 11,000 specimens, it is by 

 far the most important series of these crustaceans ever collected from 

 the southeastern United States. The Operation Crossroads investi- 

 gations yielded over 8,000 miscellaneous marine invertebrates from 

 the Marshall Islands. A desirable personal collection of nearly 

 3,000 worms and crustaceans from various localities came as a gift 

 from the collector, Leslie Hubricht. The type collection of Foram- 

 inifera was increased by 706 slides, bringing the total in this col- 

 lection to 10,640 slides. In the division of mollusks the largest and 

 most important of the year's accessions comprised about 200,000 speci- 

 mens collected by Associate Curator Morrison in the biological recon- 

 naissance of the Marshall Islands in connection with Operation Cross- 

 roads. The Naval Medical Research Unit No. 2 turned over to the 

 Museum 25,000 specimens, mainly of land and fresh-water mollusks, 

 from China, the Philippines, and the Marianas. Dr. A. R. Loeblich, 

 Jr., now a member of the staff of the department of geology, donated 

 1,200 marine shells from Okinawa. 



Accessions in the division of plants (including diatoms) aggregated 

 nearly 44,000 specimens, from many parts of the world. About 4,800 

 plants came as a result of Associate Curator Morton's botanical field 

 work in St. Vincent, Lesser Antilles, a region heretofore but scantily 

 represented in the National Herbarium. In transfers from the United 

 States Department of Agriculture, the Museum received 5,500 grasses 

 from Brazil, collected by Jason R. Swallen, and 1,500 specimens of 

 bamboos, collected by Dr. F. A. McClure. Several other large lots 

 came from South America, the West Indies, Japan and Formosa, 

 the South Pacific, and several parts of North America. 



Geology. — The department of geology received about 4l^ times as 

 many specimens as last year, this increase being due largely to a great 

 influx of invertebrate fossils to the number of about 200,000. 



Additions in mineralogy and petrology were somewhat fewer than 

 usual, though gifts, exchanges, and purchases brought some fine new 

 minerals, gems, and meteorites to the collections. Twenty-one meteor- 



