Epipharyngeal structures of Lithobius. ALithobius (Lithobius) pyrenaicus; one row of ‘bottle-shaped’ epidermal glandular shafts; laterally narrowing transverse bulge B–CLithobius (Lithobius) validusB two rows of ‘bottle-shaped’ epidermal glandular shafts C pore of an epidermal glandular shaft (arrow) DLithobius (Ezembius) electus; broad median spine field with several rows of branching bristles and a subequal width medially and laterally. bu – transverse bulge, gl – ‘bottle-shaped’ epidermal glandular shafts.