Lydia Jacubowa obtained her docotoral degree at Zurich in 1906 for her thesis Polycladen von neu-britannien und neu-caledonien, dealing with an order of unsegmented marine worms of the class Turbellaria, from New Britain (western Pacific) and New Caledonia (part of Papua New Guinea). She then settled in Arhangel'sk (Archangel), in north-western Russia, from where she submitted a paper on "A new species of Planocera (P. Gilchristi) from South Africa". It dealt with a single specimen of the order Polycladida and was published in the Transactions of the South African Philosophical Society (1907-1908, Vol. 17, pp. 145-150). The species was named after J.D.F. Gilchrist*, who had submitted specimens to her for identification. Subsequently she also studied the Polycladida of the Bay of Sebastopol in the Black Sea (1909), and later the sedentary plants and animals living on the bottom of the Black Sea (1931).