2i2 THE HUMBLE-BEE 



VIII 



Edinburgh, in 1895 ; it has also been found freely 

 around Rugby by the Rev. F. D. Morice, and 

 in the neighbourhood of Belfast by Mr. H. L. 

 Orr. In East Kent, however, I have taken no 

 specimens except one giant male, nor have 

 I found it on collecting excursions in West 

 Kent, Sussex, and Surrey. Probably, therefore, 

 it is rare in the south-east of England, but 

 common in many places in the midlands and 

 north. 



It has been taken in Cornwall, and a male of 

 the yellow-tailed variety has been sent me by 

 Mr. Cunningham from Cargill in Perthshire. 



I have seen examples (all white-tailed) from 

 several places in Ireland. 



One would expect Ps. distinctus to breed in the 

 nests of Bonibus luconim, and this supposition is 

 favoured by the fact that at Edinburgh and Belfast 

 B. lucorum is much more abundant than B. ter- 

 restris. To settle the question Mr. Orr kindly 

 sent me a living distinctus queen from Belfast on 

 June 6, 191 1, and I introduced her to a small 

 lucorum colony whose queen was dying. She 

 made herself at home immediately, and subse- 

 quently produced 48 young, 34 being males and 

 14 females; the females were produced after the 

 males. 



It is remarkable in how many details the dif- 

 ferentiation between Ps. vestalis and Ps. distinctus 

 corresponds with that which exists between their 

 respective hosts B. terrestris and lucorum ; for 



