FIGURE 2 in DNA barcodes unite two problematic taxa: the meiobenthic Boreohydra simplex is a life-cycle stage of Plotocnide borealis (Hydrozoa: Aplanulata)

FIGURE 2. The egg of the polyp stage of Plotocnide borealis. A. SEM of the polyp with the egg, marked by (*). B. SEM of the egg, front view. C. Live image of the gastric region of the polyp with the egg. D. Transverse semi-thin section of the polyp stage stained with a mixture of toluidine blue and methylene blue clearly showing the egg. E, F. TEM of the oocyte wall, the invaginations of the outer membrane are marked by arrows.