1971] 
Hlavac — A ntenna Cleaner 
53 
the tibial apex, (Fig. 4 R. Rng). The ring and row setae are sub- 
ject to much variation in size, number and density. In addition, 
other setae may be present that are not organized into distinct 
clusters but are distributed randomly over the tibial surface. 
When the insertions of the spurs of the middle or hind tibia are 
more than slightly separated, a setal row extends above each, e.g., 
Carabus (Fig. 4). In such forms, a number of ring setae are found 
between the spurs. The medial aspect of the tibia consists then of 
some horizontal ring setae between the vertical setal rows and the 
spurs. The geometry of these setal aggregations relative to each 
other and to the spurs on the mesotibia is similar to that of the 
protiba of some carabids, e.g., Carabus , Opisthius (Figs. 7 and 
9). As a preliminary hypothesis, the setal band of the protibia 
is considered to be serially homologous to that portion of the setal 
ring between the spurs in the other legs, and the anterior and pos- 
terior rows are serially homologous to the setal rows above the 
spurs. This hypothesis assumes, of course, the existence of a similar 
setal organization on all tibiae in primitive forms before some of 
the protibial setae became densely packed and specialized for antenna 
cleaning. The evolution of the carabid protibia can be looked at as 
divergence from the unspecialized configuration of the mesotibia. 
One important component of this divergence is the modification of 
protibial structure for antenna grooming. The amount of proximal 
lengthening of the setal band is the best single indicator of pro- 
tibial specialization for antenna cleaning. 
The length of the setal band (measured along the tibial long axis 
from the anterior spur insertion to the most proximal clamp seta) 
over the total length of the tibia (up to the articular head) or SB/Tb 
X 100 is a simple measure of setal band development. This method 
underestimates the length of a sinuous or horizontal band, par- 
ticularly those of grades A and C. In the least specialized forms, 
(cicindelines, Opisthius ), the setal band is almost completely hori- 
zontal, located near the distal margin of the medial face, and SB/Tb 
is less than 10%. In carabines (except Pamborus , Jeannel 1941, 
Fig. 98), cychrines and in the nebriines the band first extends verti- 
cally for a very short distance, where it is confluent with the anterior 
row, and then swings horizontally across the medial face; SB/Tb 
is between 10 and 20 per cent. In these forms, while the band is 
shifted proximally for only a short distance, the posterior spur is 
shifted as well to maintain the geometric relationship between spurs 
and band. Much greater proximal shifts of the band are associated 
with a shift in spur position in many carabids. For example, SB/Tb 
