410 ORDERS OF PTILOTA. 



could not catch it till it settled on one, when it ran up and down, 

 its wings in motion and making a considerable buzz or hum, nearly 

 as loud as a Sesia ; it twisted about its rather long tail, and turned 

 it up like a Staphytimu. I put it under a glass and placed it in 

 the sun; it became quite furious in its confinement, and never 

 ceased running about for two hours. The elytra or processes 

 were kept in quick vibration as well as the wings ; it buzzed against 

 the sides of the glass with its head touching it, and tumbled about 

 on its back. By putting two bees (Andrena labialvi) under a glass 

 in the sun, two Stylops were produced ; the bees seemed uneasy 

 and went up towards them, but evidently with caution as if to fight, 

 and moving their antennae towards them retreated. I once thought 

 the bee attempted to seize it ; but the oddest thing was to see the 

 Stylops get on the body of the bee and ride about, the latter using 

 every effort to throw his rider. A large hole is left in the tail of 

 the bee where the Stylops escapes, which closes up after a time, 

 I have found five species of Andrena infested. When off the bee 

 the Stylops kept its wings still and half erect." 



The genus Xenos is distinguished by having both the 

 branches of the antennae inarticulate. It comprises t\vo 

 species : one found in Europe, infesting the body of the 

 Polistes Gallica (one of the social wasps) ; and the other 

 Xenos Peckii, above noticed. 



In the genus Stylops, the outer branch of the antennae is 

 flattened, and tri-articulate. This genus comprises several 

 British species, and appears confined to the genus Andrena. 



The genus Elenchus has the antennae similarly jointed, 

 but very long and slender, and the eyes scarcely peduncu- 

 lated. Type, Stylops tenuicornis of Kirby. Elenchus Tem- 

 pletonii, Westw., was discovered at the Mauritius by Mr. 

 Templeton. 



The genus Halictophagus, so named from being supposed 

 to be parasitic upon the genus of bees Halictus, has the an- 

 tennae internally furnished with four branches. A single 

 individual of H. Curtisii was taken by Mr. Dale near Lul- 

 worth Cove, Dorsetshire, by brushing long coarse grass and 

 thistles into a net. 



