REVISIONARY CLASSIFICATION OF RUTILIINI 45 
nearly all specimens, and some Ruwtilia s.l. have one or two very fine humerals 
developed and distinguishable from the hair on the inner half of the callus as well; 
though a somewhat intangible character, it does seem that the setae on the inner 
half of the callus are almost never developed in the subgenus Chrysorutilia, whereas 
at least one and usually two humerals are (even if very fine) normally differentiated 
from the hair on the inner half of the callus in other subgenera. 
An extremely important chaetotactic character among Ruitilia s.l. is the number 
of strong setae on the postalar callus, and I find this to be one of the most useful 
characters that exists (on present knowledge) for dependably segregating the species 
into their respective subgenera. This feature of the chaetotaxy, whether there are 
three postalar setae or whether there are four (or more) such setae, provides an almost 
completely dependable character for distinguishing some subgenera from others— 
though very occasional specimens are found in which there are three postalars on 
one side and four on the other. If the species of Rutilia are assembled on the basis 
of their common possession of three and four postalar setae it is found that the 
resulting groupings appear without doubt to reflect a natural dichotomy within the 
genus, and that distinct taxa (subgenera) can then be defined on the basis of several 
other characters taken in combination with the postalar character. Omitting the 
small subgenera Neorutilia and Ameniamima subgen. n. (of which the affinities are 
rather obscure) the great bulk of Rutilia species are comprised here in the present 
re-classification in five subgenera, three in the section possessing the three postalar 
setae and two in the section with four such setae. The subgenera with three 
postalars (Rutilia s.str., Microrutia and Grapholostylum) have a well developed 
anterior sternopleural seta, lack a hind tibial fringe, and have the hair of the supra- 
squamal ridge rather short and sparse, and are considered very closely allied; the 
subgenera with four postalars (or more) (Donovanius and Chrysorutilia) seem 
similarly close to each other (although their ¢ genitalia differ strikingly) and comprise 
forms without definite anterior sternopleural setae, with a well developed hind tibial 
fringe, and with extremely long thick bushy and often crinkled hair on the supra- 
squamal ridge. Distinctions between the seven subgenera recognized are em- 
phasized in more detail in the treatment of each subgenus. 
There is a strong tendency for the constituent species within each subgenus to 
have the same or similar type of colour pattern, though species may look super- 
ficially rather different because of different intensities of colour and of widely 
differing sizes. In Rutilias.str. the predominant coloration is brown with little or no 
development of metallic colouring and no spot patterns, whereas in Chrysorutilia 
the species are rather homogeneously metallic green to blue-violet, with yellow heads 
and some coppery or blackish patterning or iridescence ; in Amenitamima the colouring 
is green to purplish black, and both thorax and abdomen have a pattern formed of 
boldly marked white pollinose spots. A general indication of the range of colour 
and pattern, together with size, found in each subgenus has been given as an appendix 
to each of the subgeneric diagnoses. 
The male genitalia and the form of the 5th (subgenital) abdominal sternite of 
the male provide some characters of taxonomic value at subgeneric and specific 
| level, although very often groups of apparently distinct species have virtually 
| 


