4. The fungifaber valve pattern group

In the worker’s enteric valve, the primary cushions are of two types: the even PCs are similar to the PCs of the basic enteric valves but the odd PCs, in their downstream part, are crested and protrude within the lumen of the valve (as in Fig. 4A). The primary cushions are either fusiform (their largest width is located near the middle and their lateral margins converge gradually towards both ends) or triangular (their largest width is located near their upstream end and their lateral margins converge gradually downstream). The odd PCs bear crests that are as high as or higher than they are wide, with longer and stronger bristles (Fig. 11E). On a microscope slide, it is quite frequent that at least one of these PCs is twisted, showing the crest in profile (Fig. 11 E’). The enteric valve thus shows triradial symmetry. In some samples, however, the crests are weakly developed; their valves are then sometimes difficult to distinguish from the basic enteric valves of the bilobatodes or the muneris patterns.

An odd PC is made of (a) an upstream spiny part (18–42% of total length) with relatively strong spines, (b) a middle spiny part (34–55% of total length) with somewhat weaker spines and with 13–30 lateral supporting bristles on each side, and (c) a bristly part (21–36% of total length) with 35–85 long, straight or curved bristles on a crest generally higher than wide; behind the crest, the bristly part bears some curved or hooked bristles (Fig. 15A).

The secondary cushions are wide at the upstream end, narrowing noticeably downstream with a homogeneous spine scattering (Fig. 15A).

In the soldier’s enteric valve (Fig. 15B), the crests (on the odd PCs) are generally absent or weakly developed, and often their valves can hardly be distinguished from the basic enteric valves of the bilobatodes or muneris patterns. The secondary cushions are like those of workers but bear less developed spines.

The imago’s enteric valve is much smaller than those of the soldiers and workers; the primary cushions are simple, without any crest, the secondary cushions are wide and homogeneous (Fig. 15C).

This basic valve pattern is therefore characterised by high and narrow hairy crests on the downstream end of the odd PCs; most species are large.

Material examined

Eleven species have such enteric valves: