INTRODUCTION. 



The total number of British species of Bees known at present is 211, 

 which number only slightly exceeds that contained in the first 

 edition of this work, some of the forms therein enumerated as 

 distinct species having proved to have been founded on sexual cha- 

 racters. Ten species are entirely new additions to this part of the 

 British fauna, whilst two, formerly believed to be British, have been 

 omitted (SpJwcodes fusc'qiennis and Andrena Jcirbyi). Other errors 

 have been corrected and the synonyms carefully revised. All the 

 types of Kirby's Monograph have been reexamined, and the species 

 contained in the Stephensian, Curtisian, Linnean, and Banksian col- 

 lections have been again referred to. 



Whenever practicable, the descriptions have been prepared from 

 specimens in the tin est possible condition ; and, in accordance with 

 the former edition, French measurement has been used. When both 

 sexes have been described as distinct species by an author in the 

 same work, the specific name given to the male has in every instance 

 been adopted. 



The letters B.M. indicate that the species is represented in the 

 collection of the British Museum. 



FREDERICK SMITH. 



British Museum, 

 Nov. 1870. 



