1971] 
Hlavac — Antenna Cleaner 
6 3 
1 ) the nature of putative reductions of the antenna cleaner 
mechanism, and 
2) correlation of presence of either grade A or B cleaners with 
that of another presumably primitive character — the open procoxal 
cavity. 
Reduction of the antenna cleaner is found in very few groups. 
In several ozaenine genera, e.g., Platycerozaena (Figs. 30, 31), 
Physea , Ozaena (Banninger 1927, Figs. 1, 2, 7) the curvature of 
the cleaning arc is reduced and the antennal sensory regions are very 
much smaller than those of related genera, e.g., Tropopsis (Figs. 
26, 27). 
A very long, straight setal band is present in primitive paussids, 
e.g., Protopaussus, Carabidomemnus , Eohomopterus and some species 
of Arthropterus. In these forms, the antennae are not greatly modi- 
fied and bear a moderate number of setae. The setal band is absent 
in other paussines, where the antennal segments may be greatly 
dilated and fused together (Darlington 1950: 60-65, Figs. 45-103, 
I 20-127). 
The antennae of Adelotopus (Pseudomorphinae) are not as long 
as the head and bear very few setae and sensillae. The antenna 
cleaner is greatly reduced, and may no longer be used in grooming. 
It consists of a few widely spaced setae arranged in a vertical row 
between the spurs. A single large straight seta near the posterior 
spur is probably a vestigial clip seta. In related genera, e.g., Sphal- 
lomorpha the antenna is long, bears dense setation, and the cleaner 
is a normal grade C type. 
In each case, both the antenna and the cleaner have undergone 
reduction. Furthermore, the grade C cleaners are simply reduced ; 
there is no evidence of reversal towards a grade B configuration. 
The setose regions of forms with either grade A or B cleaners are 
quite variable in size, but except for the trachypachidines, they are 
much larger than in the forms cited above as examples of reduction. 
Except for Gehringia , carabids with open procoxal cavities have 
either a grade A or B antenna cleaner, while forms with closed 
coxal cavities have either a grade B or C cleaner, except for the 
cicindelines and Enceladus (Table 1). Closed coxal cavities and 
related structures represent a mechanical improvement in the pro- 
mesothoracic joint. Open cavities are probably primitive in carabids, 
(Hlavac, unpublished observations). Improvement of the antenna 
cleaner is then correlated with improvement of the pro-mesothoracic 
j oint. 
Reduction of the antenna cleaner mechanism is a rare phenomenon. 
