74 t'-^i"-'!' 



forwards in the middle, but not reaching the line of the spiracles. There 

 is no othei" dark banding or suffusion in mv specimens. At present I 

 have not examined the $ parasites from the very closely allied species, 

 A. minufula, ))io?'iceIIa, suhopaca, and fahijica, but as T can see no 

 difference between those from A. spreta and saundersella (^nana auct. 

 plur.) I think the others are likely to be the same. I have several times 

 bred the 6 of this little Stylops, but not recently, the last I secured 

 being in 1898 or 1899 at Fordham, near Cambridge, but these and 

 others I gave away to Coleopterists. 



HALiCTOXEJfus Pierce. 



This genus was formed by Pierce for American species of Stylojyidae 

 infesting the group of metallic Salicti (known sometimes as ChJora- 

 lictus), and was placed by him in his family Xeiiidae, the species of 

 which are mostly parasitic on wasps and fossorial wasps. A subgenus, 

 HaJictophilus, was made for two Asiatic species, while a second genus, 

 Halictostylops, for the European species infesting Halictits minutus 

 was erected on the strength of Xassonow's figui-e ! I suspect that these 

 genera will prove to be so intimately connected as to be inseparable, and 

 I have used for the British species the lirst name used, Halictoxenus. 

 I have myself frequently obtained female Halictoxenus in II . nitidius- 

 culus, a species so closely allied to H. minutus that it is often confused 

 \vith it in collections. This latter species has also been recorded as sty- 

 lopized in England, but I should not depend on the true identification of 

 the host by the recorders. Most likely, however, both have the same 

 parasite. My specimens from S. nitidiusculus do not agi-ee with 

 Pierce's description taken from Xassonow's figure, but I attach no im- 

 portance to the differences. Even recently some Hymenopterists have 

 used the name Halictopliagus for the stylopid parasites of Halictus^ 

 but as I pointed out in 1905, this name was an unfortunate creation by 

 Cm-tis, who, probably at Dale's suggestion and on the feeblest kind of 

 evidence, conjectm-ed that Halictus was the host, while the true one was, 

 no doubt, some Jassid in the Homoptera. 



1. — Halictoxenus spencii Nassonow. 



Local, but sometimes not rare in Halictus nitidiusculus. I have 

 several times found the bee with the empty 6 puparimn, but have never 

 l)een able to breed this sex. The specimens examined by me are approxi- 

 mately '9 mm. broad across the spiracles and '7 long from the hind 

 margin of these to the middle of the front margin of the head, measured 

 in a stj-aiii:ht line. The basal dark band does not reach the line' of the 



