HENRY J. FRANKLIN. 181 



rejected on this account." Psithyrus must, therefore, be 

 used as the correct name for the genus of " guest bumble- 

 bees." 



This family of bees, the genus Bombus especially, has 

 probably received more attention from entomologists than 

 has any other, the Apidae excepted. This has been due, 

 for the most part, to a certain conspicuousness caused by 

 size and abundance. Their social habits have also induced 

 much special study. Among the more prominent European 

 workers on the classification of the family, the following 

 may be particularly mentioned : Fabricius, Latreille, Kirby, 

 Dahlbom, Lepeletier, Illiger, Nylander, Schenck, Thomson, 

 Smith, Gerstaecker, Morawitz, Kriechbaumer, Schmiede- 

 knecht, Radoszkowski, Handlirsch and Friese. The work 

 of Schmiedeknecht has been of especial importance, as he 

 was the first to really bring order out of chaos among the 

 European species which had become badly mixed up princi- 

 pally on account of an even more remarkable variation of 

 color characters than that exhibited by the American species 

 in general. In America the pioneer work of Cresson has 

 been the most important and the most accurate of all. Sev- 

 eral other American workers have, however, contributed 

 much of value. Among these may be mentioned Provan- 

 cher, Greene, Cockerell, Ashmead, Viereck, Robertson, 

 Titus, Crawford, Swenk and Morrill. Of American workers, 

 Putnam, Cresson and Packard have published considerable 

 of value on the habits of the Bombidse, but the most im- 

 portant work along this line has been done by Europeans, 

 among whom we may particularly mention Hoffer, Hiiber 

 and Reaumur of the older writers, and Schmiedeknecht, 

 Friese, Wagner and Buttel-Reepen of those more recent. 



Several attempts have been made to divide the genus 

 Bombus up into natural groups or sections and to indicate 

 to some extent the relationship of its species. Except the 

 work of General O. Radoszkowski and of Robertson, along 

 this line, all such attempts have, up to this time, been but 

 little better than guesswork. All, except Radoszkowski and 

 Robertson, have based their conclusions concerning relation- 



TRANS. AM. ENT. SCO., XXXVIII. 



