180 american hymenoptera. 



History of Bombid^. 

 All the older Hymenopterists included the species of Bom- 

 bus and Psithyrus in the great genus Apis, and they were re- 

 tained there until after Kirby and a few others had noted the 

 peculiar habits of Bombus and had published descriptions of 

 the principal characters in which they differ from Apis and 

 other bee genera, and had in entomological literature called 

 them Bombinatrices. In 1802, Latreille established the genus 

 Bombus to include indiscriminately both the true bumble-bees 

 and the guest bumble-bees. William Kirby (in 1802) was 

 the first to observe the more noticeable structural differences 

 between the females of the true bumble-bees and of their inqui- 

 lines, but he did not know anything of the habits of the latter. 

 Illiger in 1806, followed by Dahlbom in 1832, made a second 

 division of the bumble-bees to contain the species the females 

 of which were without corbiculae. Lepeletier, in 1832, made 

 a genus of this division, giving it the name Psithyrus, and in 

 the same paper indicated a parasitic or inquilinous habit for 

 the species to be placed in it. Two years later, Newman, 

 probably in ignorance of the fact that a name had already 

 been given, gave the genus the name Apathus. These two 

 names have both been much used by later workers on this 

 family, and it is only comparatively recently that the name 

 Psithyrus has become firmly established and constantly used. 

 Moreover, some authors continued to place these species in 

 Bombus for many years after the name Psithyrus was given. 

 Greene placed them in Bombus in 1860 and Gerstaecker did 

 likewise as late as 1869. Frederick Smith used the name 

 Apathus, as he considered that Psithyrus had been preoc- 

 cupied by HUbner in 1816 for a genus of Lepidoptera. Hiib- 

 ner, however, did not use the name Psithyrus, his spelling 

 having been " Psithyros'' Touching on this close similarity 

 of names, the International Code of Zoological Nomencla- 

 ture, in its recommendations under Article 36, says, "It is 

 well to avoid the introduction of new generic names which 

 differ from generic names already in use only in termination 

 or in a slight variation in spelling which might lead to con- 

 fusion. But when once introduced such names are not to be 



