94 KW, GCROSSIEGE ¥ 
that most of the characteristics of Amphibolia conform exactly or very closely with 
those of Rutilia in the wide sense and that it is difficult to find really convincing 
characters for generic separation. The type-species, A. valentina, remained for 
many years the only known species and seemed very distinct from all the Rutilia 
species because of the exceptionally unusual and conspicuous bold black-and-white 
pattern of the thorax and abdomen, a pattern that elsewhere in the Rutiliinioccurred 
only in the superficially similar species Formosia speciosa Erichson; now, however, 
that more species are known through the work of Paramonov (1950, 1968) it is clear 
that valentina is not nearly so distinctive as it seemed, and that other species of 
Amphibolia such as A. campbelli Paramonov, though having the black-and-white 
pattern, have features of the facies, strength and arrangement of the chaetotaxy 
and so forth that suggest rather close affinity to, particularly, the segregates Param- 
phlibolia and Chaetogastrina. The two species contained in these hitherto monotypic 
genera look very different from Amp/ibolia when arranged in a collection, because 
they lack the black-and-white pattern, yet they do not differ (apart from pattern) 
from typical Amphibolia on their structural characters to any greater extent than do 
many of the species of Rutilia or Formosia differ from their more typical congeners. 
Considering the range of known species in Amphibolia, Paramphibolia and Chaeto- 
gastrina as a whole, therefore, it seems best to treat them in an equivalent manner to 
the species here placed in Rutilia s.1. by merging them into a single genus and widen- 
ing the generic definition of Amp/ibolia accordingly. But the form of the male 
hypopygium and fifth sternite which is essentially very similar in assimilis and 
stolida (type-species respectively of Paramphibolia and Chaetogastrina) differs 
slightly from that of typical Amphibolia species, and for this reason (taken in 
conjunction with the striking pattern difference) it is considered best to recognize 
two subgenera, distinguished by the same order of difference as that distinguishing 
the various subgenera here recognized in Formosia and Rutilia. 
The main characteristics distinguishing Amphibolia s.l. from other Rutiliine 
genera are as follows: suprasquamal ridge haired (distinction from Formosia, 
Formodexia, Chetogaster, Rutilodexia and Prodiaphania), postalar callus with three 
or four setae (distinction from Chetogaster), palpi normal and arista micropubescent 
(distinction from Prodiaphania); head entirely pollinose, non-metallic (distinction 
from Chrysopasta) ; facial carina contracted or evanescent ventrally (distinction from 
Rutilia s.1.); intermediate abdominal tergites (T3 and T4) almost always with discal 
setae (distinction from all other genera except Chetogaster). 
Amphibolia s.l. is most nearly allied to Rutilia, and the distinctions between these 
time-honoured genera are rather intangible. In general in Rutilia the facial carina is 
rather broad, often flattened on the fore surface, and not strikingly evanescent at its 
ventral end, whereas in Amphibolia the carina is conspicuously best developed on the 
upper part (which may be obviously bulbous) and weakly developed with the sides 
much convergent at the ventral end. Nearly always in Amphibolia there are a few 
erect discal setae present on tergites 3 and 4, but occasionally specimens lack 
abdominal discal setae on these tergites or one of the tergites may have only a 
single seta; on the other hand discal setae are apparently never present on the 
intermediate tergites in Rutilia (though doubtless some specimens of this genus will 
