72 REPORT OF NATIONAL MUSEUM, 1923. 



cially in his work on the East Indian collections made by Dr. W. L. 

 Abbott. To James P. Chapin, of the American Museimi of Natural 

 History, the division is indebted for the determination of some 

 African weaver-birds sent him, and to W. E. Clyde Todd, of the 

 Carnegie Museum. Pittsburgh, Pa., for the determination of some 

 South American fly-catchers. Dr. E. R. Dunn, of Smith College, 

 has been constantly drawn upon for identification of difficult sala- 

 manders. A. I. Ortenburger, of the American Museum of Natural 

 History, New York, has continued his work on the North American 

 snakes of the genus Coluber, and Dr. F. N, Blanchard, of the Museum 

 of the University of Michigan, his studies of the North American 

 water snakes (Natrix), In the division of fishes Henry W. Fowler, 

 of the Academy of Natural Sciences, Philadelphia, Pa., has cooper- 

 ated as heretofore. 



The researches of the Bureau of Entomology, Department of Agri- 

 culture, are so intimately interwoven with the collections of the 

 division of insects that as a whole they may be claimed as for the 

 benefit of the Museum, and to single out the work of individuals, not 

 custodians of sections, would be invidious, except perhaps where it 

 has resulted during the year in manuscripts submitted for publica- 

 tion, such as the paper by R. A. Cushman " On the genera of the 

 Ichneumon flies " etc., and R. A. St. George's " Studies on the larvae 

 of North American Beetles." Dr. R. V. Chamberlin, of the Museum 

 of Comparative Zoology, has kindly continued his assistance in deter- 

 mining specimens of spiders and myriopods. as there is no specialist 

 in these groups in Washington. Prof. T. D. A. Cockerell. of the 

 University of Colorado, has been one of our most valued collabo- 

 rators. Dr. F. F. Laidlaw. of Devon. England, has completed another 

 portion of his work on dragon-flies of the East Indies (Museum 

 material) and the manuscript has been received for publication. 

 Extensive collections of unidentified material in various groups have 

 been sent to outside investigators for the benefit of the Museum, such 

 as bumblebees to Mr. T. H. Frison, University of Illinois, bees of 

 the genus Trigona to Dr. F. E. Lutz. of The American Museum of 

 Natural History, scorpions to Prof. William Patten, of Dartmouth 

 College, stone-flies to Prof. P. W. Claassen. of Cornell University. 

 Alaskan horse-flies to Prof. J. S. Hine, Ann Arbor, Mich. : flies of the 

 genus Gonia to Dr. John Tothill, Fredericton, New Brunswick, etc. 



The lack in Washington of specialists in numerous groups of 

 invertebrates, outside of mollusks, echinoderms, and insects, has 

 made the division of marine invertebrates dependent on the gen- 

 erous assistance of students all over the country, whom the curator 

 has designated as his " volunteer staff," and to whom the Museum is 

 greatly indebted. It includes the following names together with the 



