FIGURE 3 in Structure and phylogenetic significance of the sternum V glands in Trichoptera 2884

FIGURE 3. Drawings based on wholemounts (A–C) or histological sections (D). The drawings based on wholemounts are viewed through the cuticle, anterior is to the left with down being mesal; thus the drawings show the left gland. Muscle fibres are grey and all structures in the wholemounts are drawn as if they were transparent. Transparency of cuticle is shown only in D where cross hatching indicates non-transparent cuticle. A–D: Philopotamidae. A and B: Dolophilodes novusamericanus female and male, respectively; note large scaly patch in female. The gland opening muscle was missing in the female, but the ventrolongitudinal musculature was missing as well, so the absence is likely due to decomposition. C and D: Chimarra obscura female. C: Co-occurring normal sternum V gland and fenestral gland, note the sunburst-like arrangement of muscle fibres associated with the fenestral gland. D: Cross section of fenestral gland with position of fenestra (transparent cuticle) indicated, also note the muscle fibres (part of the 'sunburst') that originate on the cuticle and insert on the reservoir. S IV, sternum IV; S V, sternum V; Go, gland opening; Ip, insertion point for muscle; Op, origin point for muscle; L-t, Lepidoptera-type opening muscle; Rs, gland reservoir; Sc, secretory cells; SVg, sternum V gland; Fg, fenestral gland; Tc, transparent (and perforated) cuticle.