NOMADA. 253 



tion to their prettiness of colour and elegance of form, 

 they have a further attraction in the agreeable odours 

 they emit, sometimes of a balmy or balsamical, and 

 sometimes of a mixed character, and often as sweet as 

 the pot-pourri, and occasionally pleasantly pungent. A 

 fine string of specimens of the several species is a great 

 ornament to a collection, but to secure this in its per- 

 fection some care is required in the mode of killing 

 them. Their colours are best permanently retained by 

 suffocating them with sulphur, which fixes the reds and 

 yellows in all their natural and living purity. My 

 method was in my collecting excursions to convey with 

 me a large store of pill-boxes of various sizes, and as 

 I captured insects in my green gauze bag-net, I trans- 

 ferred them separately to these boxes. When home 

 again I lifted the lids slightly on one side and placed as 

 many as would readily go beneath a tumbler, and then 

 fumigated them with the sulphur. This is a better 

 plan than killing them with crushed laurel- leaves, for it 

 leaves the limbs much longer flexible for the purposes 

 of setting, whereas the laurel has a tendency to make 

 them rigid, and this rigidity is extremely difficult to 

 relax, whereas the setting of those killed with sulphur, 

 if they are kept in a cool place, may be deferred for a 

 few days, until leisure intervene to permit it, and even 

 then if they become stiffened they are readily relaxed 

 for the purpose. 



A division might very consistently be established in 

 the genus by the separation of those which have sub- 

 clavate antennae, and the segments of whose abdomen 

 are slightly constricted ; these also are more essentially 

 midsummer insects, and usually frequent the Ragwort. 

 This is the only genus of parasites amongst the true 



