342 THE CANADIAN ENTOMOLOGIST, 



from other bees and resemblances among themselves are associated with 

 the inqiiiline habit, ignoring the characters which indicate their true 

 relationship. Mr. Ashmead's arrangement of those bees seems to me to 

 illustrate the same kind of taxonomy. If, according to Mr. Ashmead, the 

 inquilines can not form a natural group of Apida^ parasiticae on account 

 of their varied relationships to other bees, how can Coeiioxys, which 

 he admits is derived from Megachilc, and Stelis, which he admits 

 is derived from Aiithidiian, form a natural family of Stelidi^ 1 

 In the same line is the reference of all of the inquilines to separate 

 families. Even Psithyrus is referred to a special family and separated 

 from the Eombidii- by the interpolation of another family. 



Mr. Ashmead's remarks regarding Macropis and the Panurgid^e have 

 no significance, in view of the fact that he admits that PanurgidcX is not a 

 natural group; but how can recent offshoots from Andrena and Halidus 

 and offshoots from Anthophidje form a natural family ? What is to keep 

 a recent offshoot from A?idrena from being related to Andrena ? The two 

 submarginal cells can, as I have observed above, be shown to be of three 

 types, all of which must have had an independent origin from bees with 

 three submarginal cells. 



The resemblance between the tongues of Colletes and Fj-osopis seems 

 to me to be uninherited and misleading. I would follow Schmiedek- 

 necht in arranging Collet es.. 



The arrangement of the inquiline bees with the host-bees will make 

 it a little more difficult to define the groups, and will give some trouble to 

 amateurs who lack an elementary knowledge of morphology. But it will 

 bring us down to the consideration of the characters which are the most 

 important clues to relationship. 



I shall now offer what seems to me the most natural arrangement of 

 the local bees : 



(i) Ajidrenince : Andrena, Parandrena, Nomada, Colletes, Nomia. 



(2) ProsopidiuiB : Prosopis. 



(3) Haliciinie : Sphecodes, Halictus, Augochlora, Agapostemon. 



(4) Hallctoidince : Halictoides. 



(5) Melitt'uice. : ]\Iacroi)is. 



(6) Panurgincz : Pseudopanurgus, Calliopsis. 



(7) Perditince: Pe'rdita. 



