REPORT OF THE SECRETARY 41 



tions being borne in part by the Department of Agriculture and by 

 Oakes Ames, who is especially interested in the orchids of Central 

 America. During two months in the Canal Zone there were ob- 

 tained about 7,000 numbers of plants particularly desired in prepar- 

 ing a popular flora of the zone, and 8,000 numbers, including a large 

 percentage of orchids, were collected during 10 weeks in Costa Rica 

 for use in preparing the flora of all Central America. 



An expedition to the west coast of the United States under Dr. 

 H. G. Dyar was in the field at the close of the year, studying larvae 

 of mosquitoes. This was financed by Doctor Dyar. Dr. J. M. Al- 

 drich, associate curator of insects, was likewise at the close of the 

 year collecting Diptera throughout the high altitudes of the West 

 and on the west coast of the United States and Canada. All of this 

 material will eventually find its way into the National collections. 



During the summer of 1923 the National Geographic Society con- 

 tinued archeological explorations at the prehistoric Pueblo Bonito 

 in New Mexico under Neil M. Judd of the Museum staff. The ma- 

 terial results have not as yet been officially turned over to the Mu- 

 seum. This was the third season of explorations which are planned 

 to extend over a period of five summers. Mr. Judd had just started 

 the fourth season's work at the close of the fiscal year. 



A second expedition under the same auspices, also directed by Mr. 

 Judd, penetrated a previously unexplored section of southeastern 

 Utah, bringing back objects from basket-maker and cliff-dweller 

 habitations. 



The expedition to the Dinosaur National Monument, Utah, under- 

 taken by C. W. Gilmore, assisted by N. H. Boss, as mentioned in last 

 year's report, was completed in the middle of the summer of 1923. 

 This had for its object the procuring of one of the large dinosaurs 

 for the exhibition collections. As noted under the chapter on acces- 

 sions, sufficient material was acquired for a good skeletal mount of 

 DipJodocus, exceeding in exhibition value anything acquired in the 

 department of geology in recent years, together with a considerable 

 quantity of miscellaneous fossils representative of the Morrison 

 fauna. 



The Great Basin ranges of Nevada and Utah were the subject of 

 stratigraphic and paleontologic work by Dr. Charles E, Resser in 

 furtherance of Doctor Walcott's monographic studies. Of the fos- 

 sils collected many were from entirely new localities. 



Field work by Dr. R. S. Bassler, curator of stratigraphic paleon- 

 tology, during the year included four separate projects: (1) Field 

 work in the Central Basin of Tennessee, in cooperation with the 

 State Geological Survey, which resulted in completing the map- 

 ping of the geology of the Hollow Springs quadrangle and in 



