78 EEPORT OF NATIONAL MUSEUM, 1923. 



of marine invertebrates was sent to Daniel Cook, University of Cin- 

 cinnati; Prof. G. S. Dodds, West Virginia University; Dr. Charles 

 J. Fish, U. S. Bureau of Fisheries Laboratory, Woods Hole, Mass. ; 

 George M. Gray, curator, Marine Biological Laboratory, Woods 

 Hole, Mass.; Dr. A, G. Huntsman, Biological Board of Canada, 

 Toronto; Dr. Stanley Kemp, Dublin, Ireland; Dr. T. Odhner, Riks- 

 museet, Stockholm; Dr. A. L. Treadwell, Vassar College. Two 

 abnormal echinoids were sent to Prof. Eene Koehler for study in 

 connection with his work on variation in these animals. 



The number of plants lent to institutions or to individuals outside 

 of Washington during the past fiscal year is 1,660, comprised in 

 59 lots, considerably less than for some years past. Of these the 

 following deserve special notice : 456 specimens of Orchidaceae from 

 tropical America lent to Oakes Ames of Boston, Mass., for study in 

 connection with his critical w^ork upon American orchids, especially 

 those of Central America; 119 sheets of Carex^ sent to Kenneth K. 

 Mackenzie of Maplewood, N. J., who is monographing this difficult 

 group for the North American Flora; 125 specimens of Senecio 

 from South America, sent to the Missouri Botanical Garden for 

 study by Dr. J. M. Greenman, who is engaged in monographic work 

 upon this genus; 66 specimens of Scitaminales, lent to Prof. W. W. 

 Rowles, of Cornell University, who is preparing the account of the 

 order for the proposed flora of Central America and Panama. 



DISTRIBUTION AND EXCHANGE OF SPECIMENS. 



Duplicates distributed to high schools, colleges, institutions, etc., 

 aggregated 3,545 specimens, of which 1,490 consisted of mollusks 

 in 10 prepared sets and 608 fishes in 8 sets. 



Exchanges to the number of 28,693 were sent out, of which 2,491 

 were zoological specimens supplied by all the divisions. Of the 

 25,656 plants thus distributed, exchanges of 1,000 specimens and over 

 went sent to the Arnold Arboretum, Harvard University ; Brooklyn 

 Botanic Garden ; Field Museum of Natural History ; George Wash- 

 ington University; Gray Herbarium, Harvard University; Univer- 

 sity of Illinois; Missouri Botanical Garden, St. Louis, Mo.; New 

 York Botanical Garden; Academy of Natural Sciences, Philadel- 

 phia ; and Museo Nacional, Rio de Janeiro, Brazil. 



TOTAL NUMBEU OF SPECIMENS IN DKPABTMEXT OF BIOLOQi., INCLUDING NUMBEH OF DUPLI- 

 CATE SPECIMENS. 



From the list given below, it will be seen that the number of 

 specimens of animals and plants in the national collection is now 

 estimated to exceed 7 millions, not including the mammals and birds 

 in the custody of the Biological Survey. 



