288 
Psyche 
[December 
pygidial glands. Thus, in several myrmicine species, in which we 
(Holldobler et al 1976) and Kugler (1978) previously assumed the 
pygidial gland to be absent, we find that we now detect this organ by 
histological methods. Tables la and lb list the species of the major 
subfamilies that we investigated histologically and indicate the type 
of tergal glands found. 
b. Postpygidial gland 
Dorsal glandular structures which open posteriorly to the py- 
gidial gland, between the 7 th and 8 th abdominal terga (spiracular 
plate), we call postpygidial glands (Fig. 8). Whelden (1957, 1960) 
described glands in the 5 th gastral segment of Rhvtidoponera 
convexa and R. me tallica. For R. convexa he writes: “Even the 
largest of these is less than half the size of the fourth-segment glands 
.... In the extreme case, there may be but a single gland cell on each 
side. It is often difficult to distinguish such a unicellular gland from 
an oenocyte, despite the usually distinct difference in size of the two 
cell types. Only the identification of a duct certainly distinguishes 
such a gland from the ductless oenocyte. In many individuals this 
second pair of glands could not be found”. Whelden (1960) makes 
similar statements for R. metaUica. Our results are somewhat 
different. We found well developed postpygidial glands in the 4 
species of Rhvtidoponera investigated (Table la). In all specimens 
we found a pair of clusters of glandular cells. Each cluster contains 
about 15-20 cells and each cell sends a duct through the interseg- 
mental membrane close to the spiracular plate (Fig. 9, 10). In some 
ant species the postpygidial gland consists of only a few glandular 
cells, in others the postpygidial gland is associated with a well 
developed reservoir (Table la, lb). 
Sterna! glands 
In several species we discovered intersegmental sternal glands 
(Table 2). They can consist of a few glandular cells that send their 
channels through the intersegmental membrane, or of large clusters 
of glandular cells associated with voluminous reservoirs. These 
reservoirs are formed by invaginations of the intersegmental mem- 
branes (Fig. 8). 
In several Leptogenys species (Fig. 12) we found two large sternal 
glands with reservoirs between the 7 th and 6 th , and 6 th and 5 th sterna. 
The latter glandular organ is usually associated with a special 
cuticular structure on the 6 th sternum (Fig. 12). In Paltothyreus 
