Description of the final instar larva of Lithax musaca Malicky 1972

Biometry. Body length = 8.9 mm, head width = 1.03 mm (n= 1). All morphological characters identical to those of S. chrisiammos except as noted below.

Head. Head surface very coarsely granulated, especially between eyes (= ‘honeycomb pattern’; Figs. 18–19). In lateral view, head profile angular (Fig. 19). Frontoclypeus at height of central constriction sharply bent backwards; posterior frontoclypeal section with shallow horseshoe-shaped depression, its rim strongly marked with honeycomb pattern (Fig. 19).

Ventral apotome yellowish brown, broadly triangular; anterolateral lobes (as in L. obscurus and S. chrisiammos; Fig. 4) lacking. Postgenal suture approximately 48% of apotome length (Fig. 20).

Thorax. Pronotum surface yellowish, dark along anterior border and at posterolateral sections; very coarsely granulated in honeycomb pattern (Fig. 21). Central pronotal section with ridge-like longitudinal hump gradually descending posteriorly to pronotal surface (Fig. 21 n), thereby reaching posterior pronotal border (Fig. 22, arrow). Ridge creating pair of dark brown lateral dents (Fig. 21 d) with coarse honeycomb pattern (Fig. 23). Without obvious muscle attachment spots.

Mesonotal sclerites yellow, with triangular brown coloration on sclerite 3 tapering posteriorly; these dark patches very coarsely granulated in honeycomb pattern (Fig. 24). Mesepisternal distal section tapering to blunt apex (Fig. 25). With additional setae on proximal half of posterior faces of 1 st femora .

Abdomen. Dorsal gills present at most from 2nd segment (postsegmental position) to 7th segment (postsegmental position). Ventral gills ranging from 2nd (postsegmental) to 7th segment (postsegmental). Anal claw without accessory hook.

Case. Prepupal case flattened, 8.9 mm long, width at anterior opening 6.5 mm, at posterior opening 5.0 mm, height 3.5 mm (n = 1). Ballast stones large, up to 5x 3 mm (Fig. 26). Posterior case membrane covered by one large mineral particle (2.7x2.0 mm), as frequently observed in Lithax cases.