Fig: From Hyde, 1894, Fig 112.

Background image: Woods Hole Lab second floor laboratory, with A.H. Baldwin at microscope. Credit: Smithsonian Institution Archives. From NOAA archives gallery at https://apps-nefsc.fisheries.noaa.gov/rcb/photogallery/assorted.html

References:

Hyde, I. H., 1894. Entwicklungsgeschichte einiger Scyphomedusen. Ztschr. wiss. Zool., Bd, 58, pp. 534-565 - Fig

Hyde, I. H., 1938. Before women were human beings. Journal of the American Association of University Women, 31(4), pp.226-36.