REVISIONARY CLASSIFICATION OF RUTILIINI 9 
have use in taxonomy at supraspecific and specific levels, and indicates briefly some 
of the features which (at any rate on present evidence) have no taxonomic usefulness. 
BopDy COLOUR AND POLLINOSITY 
These are so closely interlinked, the appearance and pattern being largely deter- 
mined by the distribution of the pollinosity and its density, that they are considered 
together. Useful specific characters, and to some extent supraspecific characters, 
are provided by the extent of visible metallic coloration ; some taxa are characterized 
by having the parafrontals (sometimes also the parafacials) brilliantly metallic 
instead of pollinose (as is usual), and some have the genal dilations and epistome 
partially or entirely metallic. Metallic colouring of the abdomen is especially 
important, several segregates being characterized by the occurrence of transverse 
metallic bands or spots on most of the tergites (usually the metallic colour being 
golden green to coppery red). The presence and extent of metallic coloration on 
the abdomen provide useful characters at several levels, but in some groups there is 
conspicuous intraspecific variability; in some Chrysorutilia species, for example, 
the metallic pattern may consist of continuous transverse bands or of broken or 
partially coalesced metallic spots in the same species (and there is a tendency for 
females to have more complete banding than the males, which more frequently 
have the metallic pattern is discretely isolated spots). 
The ground colour of the head and its overlying pollinosity often provide useful 
characters for distinguishing allied species, and some supraspecific aggregates may 
have a particular head colour (a brilliant golden yellow head is a common form 
which appears in unrelated groups). The thorax normally shows traces of whitish 
pollinosity over the prescutum at least, and conspicuous spots of ‘thick’ white 
pollinosity occur in many forms in a standard pattern on the thoracic dorsum and 
often on the mesopleura and sternopleura; the presence of such bold spots is often a 
specific or group character. In some species the spots, especially those on the 
mesopleura, may have a more ‘shifting’ appearance with the direction of the light 
than in others. The mesonotum typically shows four blackish vittae, and the bold- 
ness and extent of interruption of the vittae at the transverse suture sometimes 
provide (somewhat tenuous) specific differences. Some species and groups are 
characterized by having the thorax and abdomen uniformly dark, in which case 
mesonotal vittae are not evident. 
Leg colour and, to a minor extent, antennal colour can provide useful specific 
characters. In some forms, however, such as Chrysopasta there appears to be intra- 
specific variability in leg colour, and it appears likely (but is yet to be proven) 
that some species of Microrutilia may have sexually dimorphic leg colour (black in 
males, reddish yellow in females). 
Hair colour is of no importance at the supraspecific level and its significance at the 
species level is far from clear. Several very closely related and virtually inseparable 
species differ by having either black or mainly yellow pleural hair on the thorax, 
and it is possible that some species are polymorphic in hair colour; it seems probable, 
too, that some species may be sexually dimorphic in this feature, males having black 
pleural hair and females having yellow pleural hair (as in some species of the Goniine 
