368 
Psyche 
[Vol. 88 
serve primarily for lubrication to alleviate friction between the 
sternal sclerites when the beetles flex their abdomen. But more than 
any other of the abdominal segments the last 3 tergites (VII, IX, X) 
(Fig. 6) and the 8th and 9th sternites are richly endowed with 
glandular epithelia, the individual cells of which open through pores 
in the cuticle (Fig. IB, 1C). The last two segments can be telescoped 
with especial ease into the preceding segments, and during the 
appeasement process the beetles often move them slightly back and 
forth. Furthermore, there are clusters of glandular cells with longer 
channels under the 10th tergite near the anus (Fig. 8). They resemble 
the type of cells that Holldobler (1971) located in the same position 
in Atemeles and called pygidial glands. We have, however, aban- 
doned this term, because it is very confusing, especially in the 
Aleocharinae, where the last visible tergite is usually not the 8th 
tergite (often called pygidium in the Coleoptera) but the 10th tergite. 
In addition to these hypodermal glandular structures, females and 
males possess special exocrine glandular complexes that might be 
involved in the reproductive processes but which could also play a 
role in the myrmecophilous behavior of the beetles. In the 9th 
sternite of females there are several clusters of glandular cells, the 
channels of which open through the intersegmental membrane at 
the tip of the abdomen and near the oviduct (Fig. 9). Males have 
similar glands in the 9th sternite which also open through the 
intersegmental membrane near the posterior part of the genital 
chamber (Fig. 10). Furthermore, males possess a very large gland- 
ular complex, consisting of numerous tightly packed glandular cells 
each connected with a long channel that open dorsally in bundles 
through a membrane at the genital chamber (Fig. 11). We assume 
that the secretions of this gland flow into the genital chamber. 
Females do not have this gland, but the spermathecal gland has a 
very smilar appearance. 
Finally, the hindgut might also be involved in the appeasement 
process. On several occasions we observed that beetles, upon 
presenting their abdominal tip to the ants, released a droplet at the 
anus that was licked up by the ants. 
Discussion: 
Some of the most advanced myrmecophilic relationships are 
found in the aleocharine beetles Lomechusa and Atemeles. We 
