Figure 5. A in The feeding mechanisms of Lynceus (Crustacea: Branchiopoda: Laevicaudata), with special reference to L. simiaefacies Harding

Figure 5. A, proximal region of trunk limbs 4 and 5. Endite 2 (E2) is seen overlying the gnathobases (Gn4 and Gn5) and bearing long screening setae and stout spines directed obliquely posteriorly and towards the food groove. Here some of the armature of the grid setae, e.g. at top right, consists of long dorsal setules that rest on the adjacent seta and are held in place by short, spinule-like ventral setules of that seta. Gnathobase 3 (partly visible) has twisted and reveals its densely setose outer face, which overlies the armature of the anterior margin of gnathobase 4 (revealed by its twisting), which it clearly cleans. The soft, flaccid nature of the long posteriorly directed retaining setae (RS) is obvious from the way they have been distorted during preparation of the material. Scale bar 100 Mm. B, proximal parts of trunk limbs 9 and 10, with part of 11 visible. The robust armature of the gnathobases, which sweep along the bottom of the food groove, is well displayed at the bottom of the photograph, as are numerous, mostly short, spines on the posterior margin of each gnathobase, which push and drag food material towards the food groove. These include straight spines and, as seen on gnathobase 10, curved spines that drag rather than push. The long, posteriorly directed retaining seta of gnathobase 9 is the most posterior such of the series. Because of the angle at which the gnathobase is viewed, it appears to be directed 'vertically' and is seen from its dorsal side. More distally the dense array of spines of endite 2 is displayed. To the left the posterior limit of the screen is marked by the tips of several screening setae. The armature of the more distal endites of these limbs is illustrated in Figure 8A and B. Scale bar 50 Mm.