INTRODUCTORY LETTKK. 21 



Department, Washington, D. C.; Mr. Charles H. Dodge, Agricultural 

 Department, Washington, D. C. 



Hymenoptera, Prof. E. T. Crcsson, of the American Entomological 



Society; Dr. A. S. Packard, jr., of the Essex Institute, Salem, Mass.; and 

 Mr. Edward Norton. 



Dlptri'n, Fiaron C. R. Osten-Sacken, of the Museum of Comparative 

 Zoology, Cambridge, Mass. 



llt'iiti/i/cni, Pr. 1*. R. Uhler, of the Peabody Institute, Baltimore, Md. 



Kfiiili >-x, Dr. William Ilolden, of Columbus, Ohio. 



.\i nrnji/i m, Dr. II. A. Ilageii, of the Museum of Comparative Zoology, 

 Cambridge, Mass. 



Leeches, Worms, Crustacea, and Larva, Prof. A. E. Verrill, of Yale Col- 

 lege, New Haven, Conn.; Prof. J. Leidy, of the University of Pennsylvania; 

 Dr. H. A. Hagen. 



Mallnsrii, Mr. (Jeorge W. Try on, jr., of the Academy of Natural 

 Sciences of Philadelphia; Mr. W. G. Binney, of Burlington^ N. J.; Dr. 

 .lames Lewis, of Mohawk, N. V.; and Mr. Temple Prime, of New York 

 City.. 



I have the honor to be, very respectfully, your obedient servant, 



H. C. YARROW, 

 Acting Assistant Surgeon United States Army. 



First Lieut. GEORGE M. WHEELER, 



Corps of Engineers United States Army, in charge. 



