The Semaeostomes (the name translates to “flag mouths”) are an order of jellyfish exhibiting four long, frilly oral arms. Figures 1 and 2 in this set of illustrations portray a species Haeckel named Desmonema annasethe after his wife, Anna Sethe. Anna died suddenly of an “undetermined fever” after the couple had been married only 18 months. A heartbroken Haeckel wrote the following tribute to his wife in reference to another species he named after her: 

"Mitrocoma annae belong to the most charming of all the Medusae. It was first observed by me in April 1864 in the Bay of Villafranca near Nice. Its tentacles hung like blonde hair ornaments of a princess. I named this species as a memorial to my unforgettable true wife, Anna Sethe. If I have succeeded, during my earthly pilgrimage in accomplishing something for natural science and humanity, I owe the greatest part to the ennobling influence of this gifted wife."