Ceriodaphnia megops

(Figs. 1 – 2) Length about 0.5 – 0.55 mm, width about 0.7 of length. In lateral view, ephippium almost semicircular, somewhat asymmetrical, stronger narrowing posteriorly; dorsal margin almost straight; ventral margin regularly curved from postero-ventral to antero-ventral angle (Figs. 1 A, 2 A – D). Paired latero-dorsal ridges strongly expressed (Figs. 1 B – D), extend above dorsal margin as seen laterally (Figs. 1 A, 2 A – D), their dorsal margin slightly and regularly convex. A distinct depression along dorsum separating two halves of ephippium and, respectively, two halves of dorsal plate; sculpture of dorsal plate consisting of a series of longitudinal wrinkles (Figs. 1 D – E). Sculpture on latero-dorsal ridges low, consisting of small semicircular projections (Figs. 1 D – F); the external signs of roundedhexagonal air-spaces well-visible under light microscope (Fig. 2 E). Egg locule smooth, only somewhat extending laterally, with poorly expressed vertical wrinkles (Fig. 1 B, F – G); under optical microscope, surface of locule relatively smooth, with small irregularities (Fig. 2 E). Rest of ephippium surface covered by low, dense, flattened domes (Figs. 1 G – H); the external signs of air-spaces well-visible under light microscope (Figs. 2 D, F). Such air spaces absent in the locule region. Ventral rim of ephippium lacking air spaces, with obscure polygonal reticulation (Figs. 1 H, 2 F).