178 AMERICAN HYMENOPTERA. 



lowing gentlemen : Messrs. J, C. Crawford, H. L. Viereck, 

 E. T. Cresson, Sr., Wm. Beutenmiiller, J. C. Bridwell, and E. 

 Daecke, Prof. T. D. A. Cockerell, Prof. R. A. Cooley, Prof. 

 C. W. Johnson, Judge P. G. Bolster of Boston, Dr. Heinrich 

 Friese of Germany, Prof. H. A. Surface, Prof. Franklin Sher- 

 man, Jr., Prof. V. L. Kellogg, Prof. E. S. G. Titus, Prof. 

 C. P. Gillette and Prof. E. D. Sanderson. Gratitude is hereby 

 also expressed to Dr. Henry Skinner for the privilege of 

 studying the types and other material in the collection of the 

 American Entomological Society, to Mr. Samuel Henshaw 

 for the privilege of examining the bumble-bee collection of 

 the Museum of Comparative Zoology and for assistance with 

 literature, to Dr. L. O. Howard for the privilege of studying 

 the types in the collection of the United States National Mu- 

 seum and for the loan of the rest of the bumble-bee material 

 in that Museum, to Prof. C. P. Lounsbury of Cape Colony 

 for gathering information concerning the growing and seed- 

 ing of red clover in South Africa, and to Prof. W. W. Frog- 

 gatt of New South Wales for information concerning the 

 growing and seeding of red clover in Australia, and concern- 

 ing the attempted introduction of bumble-bees into that coun- 

 try. Indebtedness to the three following gentlemen, who, 

 since this aid was given, have closed their earthly labors, is 

 also acknowledged : Dr. James Fletcher and Dr. W. H. Ash- 

 mead for the loan of specimens, and Colonel C. T. Bingham 

 for information concerning the types deposited in the British 

 Museum. 



Practically all of the types of species described by the New 

 World workers on this group have been seen and carefully 

 examined by the writer, and considerable effort has also been 

 put forth to gain more definite knowledge concerning the 

 types of New World species which have been described by 

 European workers and deposited in European museums. 



The bibliographies of the genera and subgenera have been 

 made as full and complete as any future worker on the group 

 will probably wish to have them, and no pains have been 

 spared to make the bibliography of every species included 

 in this paper absolutely complete. The writer has himself 



